Merge branch 'master' into core-updates

 Conflicts:
	gnu/local.mk
	gnu/packages/bioinformatics.scm
	gnu/packages/django.scm
	gnu/packages/gtk.scm
	gnu/packages/llvm.scm
	gnu/packages/python-web.scm
	gnu/packages/python.scm
	gnu/packages/tex.scm
	guix/build-system/asdf.scm
	guix/build/emacs-build-system.scm
	guix/profiles.scm

30 files changed, 473 insertions, 759 deletions

diff --git a/guix/android-repo-download.scm b/guix/android-repo-download.scm
index 5ff3e7edd4..1c3502e673 100644
--- a/guix/android-repo-download.scm
+++ b/guix/android-repo-download.scm
@@ -78,6 +78,9 @@ generic name if unset."
   (define zlib
     (module-ref (resolve-interface '(gnu packages compression)) 'zlib))
 
+  (define guile-json
+    (module-ref (resolve-interface '(gnu packages guile)) 'guile-json-4))
+
   (define gnutls
     (module-ref (resolve-interface '(gnu packages tls)) 'gnutls))
 
@@ -99,7 +102,7 @@ generic name if unset."
 
   (define build
     (with-imported-modules modules
-      (with-extensions (list gnutls)
+      (with-extensions (list gnutls guile-json) ;for (guix swh)
         #~(begin
             (use-modules (guix build android-repo)
                          (guix build utils)
diff --git a/guix/build-system/asdf.scm b/guix/build-system/asdf.scm
index 7bf2f97992..79de2ee5ba 100644
--- a/guix/build-system/asdf.scm
+++ b/guix/build-system/asdf.scm
@@ -1,6 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2016, 2017 Andy Patterson <ajpatter@uwaterloo.ca>
-;;; Copyright © 2019, 2020 Guillaume Le Vaillant <glv@posteo.net>
+;;; Copyright © 2019, 2020, 2021 Guillaume Le Vaillant <glv@posteo.net>
 ;;; Copyright © 2021 Ludovic Courtès <ludo@gnu.org>
 ;;;
 ;;; This file is part of GNU Guix.
@@ -279,16 +279,16 @@ set up using CL source package conventions."
                  (imported-modules %asdf-build-system-modules)
                  (modules %asdf-build-modules))
 
-    ;; FIXME: The definition of 'systems' is pretty hacky.
-    ;; Is there a more elegant way to do it?
     (define systems
       (if (null? (cadr asd-systems))
-          `(quote
-            ,(list
-              (string-drop
-               ;; NAME is the value returned from `package-full-name'.
-               (hyphen-separated-name->name+version name)
-               (1+ (string-length lisp-type)))))  ; drop the "<lisp>-" prefix.
+          ;; FIXME: Find a more reliable way to get the main system name.
+          (let* ((lisp-prefix (string-append lisp-type "-"))
+                 (package-name (hyphen-separated-name->name+version
+                                (if (string-prefix? lisp-prefix name)
+                                    (string-drop name
+                                                 (string-length lisp-prefix))
+                                    name))))
+            `(quote ,(list package-name)))
           asd-systems))
 
     (define builder
diff --git a/guix/build/asdf-build-system.scm b/guix/build/asdf-build-system.scm
index 6ad855cab2..7f1037c4f9 100644
--- a/guix/build/asdf-build-system.scm
+++ b/guix/build/asdf-build-system.scm
@@ -1,6 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2016, 2017 Andy Patterson <ajpatter@uwaterloo.ca>
-;;; Copyright © 2020 Guillaume Le Vaillant <glv@posteo.net>
+;;; Copyright © 2020, 2021 Guillaume Le Vaillant <glv@posteo.net>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -52,12 +52,13 @@
   (string-append %source-install-prefix "/systems"))
 
 (define (main-system-name output)
-  (let ((package-name (package-name->name+version
-                       (strip-store-file-name output)))
-        (lisp-prefix (string-append (%lisp-type) "-")))
-    (if (string-prefix? lisp-prefix package-name)
-        (string-drop package-name (string-length lisp-prefix))
-        package-name)))
+  ;; FIXME: Find a more reliable way to get the main system name.
+  (let* ((full-name (strip-store-file-name output))
+         (lisp-prefix (string-append (%lisp-type) "-"))
+         (package-name (if (string-prefix? lisp-prefix full-name)
+                           (string-drop full-name (string-length lisp-prefix))
+                           full-name)))
+    (package-name->name+version package-name)))
 
 (define (lisp-source-directory output name)
   (string-append output (%lisp-source-install-prefix) "/" name))
diff --git a/guix/build/download.scm b/guix/build/download.scm
index a22d4064ca..b14db42352 100644
--- a/guix/build/download.scm
+++ b/guix/build/download.scm
@@ -2,6 +2,7 @@
 ;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
 ;;; Copyright © 2017 Tobias Geerinckx-Rice <me@tobias.gr>
+;;; Copyright © 2021 Timothy Sample <samplet@ngyro.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -34,6 +35,8 @@
   #:use-module (srfi srfi-19)
   #:use-module (srfi srfi-26)
   #:autoload   (ice-9 ftw) (scandir)
+  #:autoload   (guix base16) (bytevector->base16-string)
+  #:autoload   (guix swh) (swh-download-directory)
   #:use-module (ice-9 match)
   #:use-module (ice-9 format)
   #:export (open-socket-for-uri
@@ -626,10 +629,54 @@ Return a list of URIs."
     (else
      (list uri))))
 
+(define* (disarchive-fetch/any uris file
+                               #:key (timeout 10) (verify-certificate? #t))
+  "Fetch a Disarchive specification from any of URIS, assemble it,
+and write the output to FILE."
+  (define (fetch-specification uris)
+    (any (lambda (uri)
+           (false-if-exception*
+            (let-values (((port size) (http-fetch uri
+                                                  #:verify-certificate?
+                                                  verify-certificate?
+                                                  #:timeout timeout)))
+              (let ((specification (read port)))
+                (close-port port)
+                specification))))
+         uris))
+
+  (define (resolve addresses output)
+    (any (match-lambda
+           (('swhid swhid)
+            (match (string-split swhid #\:)
+              (("swh" "1" "dir" id)
+               (format #t "Downloading ~a from Software Heritage...~%" file)
+               (false-if-exception*
+                (swh-download-directory id output)))
+              (_ #f)))
+           (_ #f))
+         addresses))
+
+  (format #t "Trying to use Disarchive to assemble ~a...~%" file)
+  (match (and=> (resolve-module '(disarchive) #:ensure #f)
+                (lambda (disarchive)
+                  (cons (module-ref disarchive '%disarchive-log-port)
+                        (module-ref disarchive 'disarchive-assemble))))
+    (#f (format #t "could not load Disarchive~%")
+        #f)
+    ((%disarchive-log-port . disarchive-assemble)
+     (match (fetch-specification uris)
+       (#f (format #t "could not find its Disarchive specification~%")
+           #f)
+       (spec (parameterize ((%disarchive-log-port (current-output-port)))
+               (false-if-exception*
+                (disarchive-assemble spec file #:resolver resolve))))))))
+
 (define* (url-fetch url file
                     #:key
                     (timeout 10) (verify-certificate? #t)
                     (mirrors '()) (content-addressed-mirrors '())
+                    (disarchive-mirrors '())
                     (hashes '())
                     print-build-trace?)
   "Fetch FILE from URL; URL may be either a single string, or a list of
@@ -693,6 +740,18 @@ otherwise simply ignore them."
                               hashes))
                 content-addressed-mirrors))
 
+  (define disarchive-uris
+    (append-map (match-lambda
+                  ((? string? mirror)
+                   (map (match-lambda
+                          ((hash-algo . hash)
+                           (string->uri
+                            (string-append mirror
+                                           (symbol->string hash-algo) "/"
+                                           (bytevector->base16-string hash)))))
+                        hashes)))
+                disarchive-mirrors))
+
   ;; Make this unbuffered so 'progress-report/file' works as expected.  'line
   ;; means '\n', not '\r', so it's not appropriate here.
   (setvbuf (current-output-port) 'none)
@@ -705,15 +764,20 @@ otherwise simply ignore them."
        (or (fetch uri file)
            (try tail)))
       (()
-       (format (current-error-port) "failed to download ~s from ~s~%"
-               file url)
-
-       ;; Remove FILE in case we made an incomplete download, for example due
-       ;; to ENOSPC.
-       (catch 'system-error
-         (lambda ()
-           (delete-file file))
-         (const #f))
-       #f))))
+       ;; If we are looking for a software archive, one last thing we
+       ;; can try is to use Disarchive to assemble it.
+       (or (disarchive-fetch/any disarchive-uris file
+                                 #:verify-certificate? verify-certificate?
+                                 #:timeout timeout)
+           (begin
+             (format (current-error-port) "failed to download ~s from ~s~%"
+                     file url)
+             ;; Remove FILE in case we made an incomplete download, for
+             ;; example due to ENOSPC.
+             (catch 'system-error
+               (lambda ()
+                 (delete-file file))
+               (const #f))
+             #f))))))
 
 ;;; download.scm ends here
diff --git a/guix/build/emacs-build-system.scm b/guix/build/emacs-build-system.scm
index 79a1a42c4a..ba2c1b4aad 100644
--- a/guix/build/emacs-build-system.scm
+++ b/guix/build/emacs-build-system.scm
@@ -26,13 +26,16 @@
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-11)
   #:use-module (srfi srfi-26)
+  #:use-module (ice-9 format)
+  #:use-module (ice-9 ftw)
   #:use-module (ice-9 rdelim)
   #:use-module (ice-9 regex)
   #:use-module (ice-9 match)
   #:export (%standard-phases
             %default-include
             %default-exclude
-            emacs-build))
+            emacs-build
+            elpa-directory))
 
 ;; Commentary:
 ;;
@@ -40,9 +43,12 @@
 ;;
 ;; Code:
 
-;;; All the packages are installed directly under site-lisp, which means that
-;;; having that directory in the EMACSLOADPATH is enough to have them found by
-;;; Emacs.
+;;; The location in which Emacs looks for packages.  Emacs Lisp code that is
+;;; installed there directly will be found when that directory is added to
+;;; EMACSLOADPATH.  To avoid clashes between packages (particularly considering
+;;; auxiliary files), we install them one directory level below, however.
+;;; This indirection is handled by ‘expand-load-path’ during build and a
+;;; profile hook otherwise.
 (define %install-dir "/share/emacs/site-lisp")
 
 ;; These are the default inclusion/exclusion regexps for the install phase.
@@ -73,40 +79,51 @@ archive, a directory, or an Emacs Lisp file."
         #t)
       (gnu:unpack #:source source)))
 
-(define* (add-source-to-load-path #:key dummy #:allow-other-keys)
-  "Augment the EMACSLOADPATH environment variable with the source directory."
+(define* (expand-load-path #:key (prepend-source? #t) #:allow-other-keys)
+  "Expand EMACSLOADPATH, so that inputs, whose code resides in subdirectories,
+are properly found.
+If @var{prepend-source?} is @code{#t} (the default), also add the current
+directory to EMACSLOADPATH in front of any other directories."
   (let* ((source-directory (getcwd))
          (emacs-load-path (string-split (getenv "EMACSLOADPATH") #\:))
-         ;; XXX: Make sure the Emacs core libraries appear at the end of
-         ;; EMACSLOADPATH, to avoid shadowing any other libraries depended
-         ;; upon.
-         (emacs-load-path-non-core (filter (cut string-contains <>
-                                                "/share/emacs/site-lisp")
-                                           emacs-load-path))
+         (emacs-load-path*
+          (map
+           (lambda (dir)
+             (match (scandir dir (negate (cute member <> '("." ".."))))
+               ((sub) (string-append dir "/" sub))
+               (_ dir)))
+           emacs-load-path))
          (emacs-load-path-value (string-append
-                                 (string-join (cons source-directory
-                                                    emacs-load-path-non-core)
-                                              ":")
+                                 (string-join
+                                  (if prepend-source?
+                                      (cons source-directory emacs-load-path*)
+                                      emacs-load-path*)
+                                  ":")
                                  ":")))
     (setenv "EMACSLOADPATH" emacs-load-path-value)
-    (format #t "source directory ~s prepended to the `EMACSLOADPATH' \
-environment variable\n" source-directory)))
+    (when prepend-source?
+      (format #t "source directory ~s prepended to the `EMACSLOADPATH' \
+environment variable\n" source-directory))
+    (let ((diff (lset-difference string=? emacs-load-path* emacs-load-path)))
+      (unless (null? diff)
+        (format #t "expanded load paths for ~{~a~^, ~}\n"
+                (map basename diff))))))
 
 (define* (build #:key outputs inputs #:allow-other-keys)
   "Compile .el files."
   (let* ((emacs (string-append (assoc-ref inputs "emacs") "/bin/emacs"))
-         (out (assoc-ref outputs "out"))
-         (site-lisp (string-append out %install-dir)))
+         (out (assoc-ref outputs "out")))
     (setenv "SHELL" "sh")
     (parameterize ((%emacs emacs))
-      (emacs-byte-compile-directory site-lisp))))
+      (emacs-byte-compile-directory (elpa-directory out)))))
 
 (define* (patch-el-files #:key outputs #:allow-other-keys)
   "Substitute the absolute \"/bin/\" directory with the right location in the
 store in '.el' files."
 
   (let* ((out (assoc-ref outputs "out"))
-         (site-lisp (string-append out %install-dir))
+         (elpa-name-ver (store-directory->elpa-name-version out))
+         (el-dir (string-append out %install-dir "/" elpa-name-ver))
          (el-files (find-files (getcwd) "\\.el$")))
     (define (substitute-program-names)
       (substitute* el-files
@@ -116,7 +133,7 @@ store in '.el' files."
              (error "patch-el-files: unable to locate " cmd-name))
            (string-append "\"" cmd "\"")))))
 
-    (with-directory-excursion site-lisp
+    (with-directory-excursion el-dir
       ;; Some old '.el' files (e.g., tex-buf.el in AUCTeX) are still
       ;; ISO-8859-1-encoded.
       (unless (false-if-exception (substitute-program-names))
@@ -167,14 +184,14 @@ parallel. PARALLEL-TESTS? is ignored when using a non-make TEST-COMMAND."
            (not (any (cut match-stripped-file "excluded" <>) exclude)))))
 
   (let* ((out (assoc-ref outputs "out"))
-         (site-lisp (string-append out %install-dir))
+         (el-dir (elpa-directory out))
          (files-to-install (find-files source install-file?)))
     (cond
      ((not (null? files-to-install))
       (for-each
        (lambda (file)
          (let* ((stripped-file (string-drop file (string-length source)))
-                (target-file (string-append site-lisp stripped-file)))
+                (target-file (string-append el-dir stripped-file)))
            (format #t "`~a' -> `~a'~%" file target-file)
            (install-file file (dirname target-file))))
        files-to-install)
@@ -205,11 +222,11 @@ parallel. PARALLEL-TESTS? is ignored when using a non-make TEST-COMMAND."
   "Generate the autoloads file."
   (let* ((emacs (string-append (assoc-ref inputs "emacs") "/bin/emacs"))
          (out (assoc-ref outputs "out"))
-         (site-lisp (string-append out %install-dir))
          (elpa-name-ver (store-directory->elpa-name-version out))
-         (elpa-name (package-name->name+version elpa-name-ver)))
+         (elpa-name (package-name->name+version elpa-name-ver))
+         (el-dir (elpa-directory out)))
     (parameterize ((%emacs emacs))
-      (emacs-generate-autoloads elpa-name site-lisp))))
+      (emacs-generate-autoloads elpa-name el-dir))))
 
 (define* (enable-autoloads-compilation #:key outputs #:allow-other-keys)
   "Remove the NO-BYTE-COMPILATION local variable embedded in the generated
@@ -244,10 +261,16 @@ second hyphen.  This corresponds to 'name-version' as used in ELPA packages."
             strip-store-file-name)
    store-dir))
 
+(define (elpa-directory store-dir)
+  "Given the store directory STORE-DIR return the absolute install directory
+for libraries following the ELPA convention."
+  (string-append store-dir %install-dir "/"
+                 (store-directory->elpa-name-version store-dir)))
+
 (define %standard-phases
   (modify-phases gnu:%standard-phases
     (replace 'unpack unpack)
-    (add-after 'unpack 'add-source-to-load-path add-source-to-load-path)
+    (add-after 'unpack 'expand-load-path expand-load-path)
     (delete 'bootstrap)
     (delete 'configure)
     (delete 'build)
diff --git a/guix/ci.scm b/guix/ci.scm
index f04109112c..c70e5bb9e6 100644
--- a/guix/ci.scm
+++ b/guix/ci.scm
@@ -43,7 +43,7 @@
 
             checkout?
             checkout-commit
-            checkout-input
+            checkout-channel
 
             evaluation?
             evaluation-id
@@ -94,7 +94,7 @@
 (define-json-mapping <checkout> make-checkout checkout?
   json->checkout
   (commit      checkout-commit)                   ;string (SHA1)
-  (input       checkout-input))                   ;string (name)
+  (channel     checkout-channel))                 ;string (name)
 
 (define-json-mapping <evaluation> make-evaluation evaluation?
   json->evaluation
diff --git a/guix/cve.scm b/guix/cve.scm
index b3a8b13a06..9e1cf5b587 100644
--- a/guix/cve.scm
+++ b/guix/cve.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2015, 2016, 2017, 2018, 2019, 2020, 2021 Ludovic Courtès <ludo@gnu.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -99,7 +99,9 @@
 
 (define (reference-data->cve-references alist)
   (map json->cve-reference
-       (vector->list (assoc-ref alist "reference_data"))))
+       ;; Normally "reference_data" is always present but rejected CVEs such
+       ;; as CVE-2020-10020 can lack it.
+       (vector->list (or (assoc-ref alist "reference_data") '#()))))
 
 (define %cpe-package-rx
   ;; For applications: "cpe:2.3:a:VENDOR:PACKAGE:VERSION", or sometimes
@@ -137,17 +139,20 @@ package."
         (starte (assoc-ref alist "versionStartExcluding"))
         (endi   (assoc-ref alist "versionEndIncluding"))
         (ende   (assoc-ref alist "versionEndExcluding")))
-    (let-values (((package version) (cpe->package-name cpe)))
-      (and package
-           `(,package
-              ,(cond ((and (or starti starte) (or endi ende))
-                      `(and ,(if starti `(>= ,starti) `(> ,starte))
-                            ,(if endi `(<= ,endi) `(< ,ende))))
-                     (starti `(>= ,starti))
-                     (starte `(> ,starte))
-                     (endi   `(<= ,endi))
-                     (ende   `(< ,ende))
-                     (else   version)))))))
+    ;; Normally "cpe23Uri" is here in each "cpe_match" item, but CVE-2020-0534
+    ;; has a configuration that lacks it.
+    (and cpe
+         (let-values (((package version) (cpe->package-name cpe)))
+           (and package
+                `(,package
+                   ,(cond ((and (or starti starte) (or endi ende))
+                           `(and ,(if starti `(>= ,starti) `(> ,starte))
+                                 ,(if endi `(<= ,endi) `(< ,ende))))
+                          (starti `(>= ,starti))
+                          (starte `(> ,starte))
+                          (endi   `(<= ,endi))
+                          (ende   `(< ,ende))
+                          (else   version))))))))
 
 (define (configuration-data->cve-configurations alist)
   "Given ALIST, a JSON dictionary for the baroque \"configurations\"
diff --git a/guix/cvs-download.scm b/guix/cvs-download.scm
index 76b3eac739..943d971622 100644
--- a/guix/cvs-download.scm
+++ b/guix/cvs-download.scm
@@ -28,7 +28,8 @@
   #:use-module (ice-9 match)
   #:export (cvs-reference
             cvs-reference?
-            cvs-reference-url
+            cvs-reference-root-directory
+            cvs-reference-module
             cvs-reference-revision
             cvs-fetch))
 
@@ -63,13 +64,20 @@ HASH-ALGO (a symbol).  Use NAME as the file name, or a generic name if #f."
   (define guile-zlib
     (module-ref (resolve-interface '(gnu packages guile)) 'guile-zlib))
 
+  (define guile-json
+    (module-ref (resolve-interface '(gnu packages guile)) 'guile-json-4))
+
+  (define gnutls
+    (module-ref (resolve-interface '(gnu packages tls)) 'gnutls))
+
   (define modules
     (delete '(guix config)
             (source-module-closure '((guix build cvs)
                                      (guix build download-nar)))))
   (define build
     (with-imported-modules modules
-      (with-extensions (list guile-zlib)
+      (with-extensions (list guile-json gnutls ;for (guix swh)
+                             guile-zlib)
         #~(begin
             (use-modules (guix build cvs)
                          (guix build download-nar))
diff --git a/guix/diagnostics.scm b/guix/diagnostics.scm
index 7b9ffc61b5..6a792febd4 100644
--- a/guix/diagnostics.scm
+++ b/guix/diagnostics.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021 Ludovic Courtès <ludo@gnu.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -233,6 +233,10 @@ etc."
           (make-location file (+ line 1) col)))
     (#f
      #f)
+    (#(file line column)
+     ;; Guile >= 3.0.6 uses vectors instead of alists internally, which can be
+     ;; seen in the arguments to 'syntax-error' exceptions.
+     (location file (+ 1 line) column))
     (_
      (let ((file (assq-ref loc 'filename))
            (line (assq-ref loc 'line))
diff --git a/guix/download.scm b/guix/download.scm
index 30f69c0325..72094e7318 100644
--- a/guix/download.scm
+++ b/guix/download.scm
@@ -406,12 +406,19 @@
   (plain-file "content-addressed-mirrors"
               (object->string %content-addressed-mirrors)))
 
+(define %disarchive-mirrors
+  '("https://disarchive.ngyro.com/"))
+
+(define %disarchive-mirror-file
+  (plain-file "disarchive-mirrors" (object->string %disarchive-mirrors)))
+
 (define built-in-builders*
   (store-lift built-in-builders))
 
 (define* (built-in-download file-name url
                             #:key system hash-algo hash
                             mirrors content-addressed-mirrors
+                            disarchive-mirrors
                             executable?
                             (guile 'unused))
   "Download FILE-NAME from URL using the built-in 'download' builder.  When
@@ -422,13 +429,16 @@ explicitly depend on Guile, GnuTLS, etc.  Instead, the daemon performs the
 download by itself using its own dependencies."
   (mlet %store-monad ((mirrors (lower-object mirrors))
                       (content-addressed-mirrors
-                       (lower-object content-addressed-mirrors)))
+                       (lower-object content-addressed-mirrors))
+                      (disarchive-mirrors (lower-object disarchive-mirrors)))
     (raw-derivation file-name "builtin:download" '()
                     #:system system
                     #:hash-algo hash-algo
                     #:hash hash
                     #:recursive? executable?
-                    #:sources (list mirrors content-addressed-mirrors)
+                    #:sources (list mirrors
+                                    content-addressed-mirrors
+                                    disarchive-mirrors)
 
                     ;; Honor the user's proxy and locale settings.
                     #:leaked-env-vars '("http_proxy" "https_proxy"
@@ -439,6 +449,7 @@ download by itself using its own dependencies."
                                  ("mirrors" . ,mirrors)
                                  ("content-addressed-mirrors"
                                   . ,content-addressed-mirrors)
+                                 ("disarchive-mirrors" . ,disarchive-mirrors)
                                  ,@(if executable?
                                        '(("executable" . "1"))
                                        '()))
@@ -492,7 +503,9 @@ name in the store."
                              #:executable? executable?
                              #:mirrors %mirror-file
                              #:content-addressed-mirrors
-                             %content-addressed-mirror-file)))))
+                             %content-addressed-mirror-file
+                             #:disarchive-mirrors
+                             %disarchive-mirror-file)))))
 
 (define* (url-fetch/executable url hash-algo hash
                                #:optional name
diff --git a/guix/git-download.scm b/guix/git-download.scm
index 425184717a..199effece5 100644
--- a/guix/git-download.scm
+++ b/guix/git-download.scm
@@ -27,6 +27,7 @@
   #:use-module (guix packages)
   #:use-module (guix modules)
   #:autoload   (guix build-system gnu) (standard-packages)
+  #:autoload   (git bindings)   (libgit2-init!)
   #:autoload   (git repository) (repository-open
                                  repository-close!
                                  repository-discover
@@ -225,6 +226,7 @@ upon Git errors, return #f instead of a predicate.
 
 The returned predicate takes two arguments FILE and STAT where FILE is an
 absolute file name and STAT is the result of 'lstat'."
+  (libgit2-init!)
   (catch 'git-error
     (lambda ()
       (let* ((files  (git-file-list directory))
diff --git a/guix/hg-download.scm b/guix/hg-download.scm
index bd55946523..c6cee2dbb8 100644
--- a/guix/hg-download.scm
+++ b/guix/hg-download.scm
@@ -65,6 +65,12 @@ HASH-ALGO (a symbol).  Use NAME as the file name, or a generic name if #f."
   (define guile-zlib
     (module-ref (resolve-interface '(gnu packages guile)) 'guile-zlib))
 
+  (define guile-json
+    (module-ref (resolve-interface '(gnu packages guile)) 'guile-json-4))
+
+  (define gnutls
+    (module-ref (resolve-interface '(gnu packages tls)) 'gnutls))
+
   (define modules
     (delete '(guix config)
             (source-module-closure '((guix build hg)
@@ -72,7 +78,8 @@ HASH-ALGO (a symbol).  Use NAME as the file name, or a generic name if #f."
 
   (define build
     (with-imported-modules modules
-      (with-extensions (list guile-zlib)
+      (with-extensions (list guile-json gnutls ;for (guix swh)
+                             guile-zlib)
         #~(begin
             (use-modules (guix build hg)
                          (guix build download-nar))
diff --git a/guix/http-client.scm b/guix/http-client.scm
index a2e11a1b73..10bc278023 100644
--- a/guix/http-client.scm
+++ b/guix/http-client.scm
@@ -38,7 +38,7 @@
   #:use-module (guix utils)
   #:use-module (guix base64)
   #:autoload   (gcrypt hash) (sha256)
-  #:autoload   (gnutls) (error/invalid-session)
+  #:autoload   (gnutls) (error/invalid-session error/again error/interrupted)
   #:use-module ((guix build utils)
                 #:select (mkdir-p dump-port))
   #:use-module ((guix build download)
@@ -163,7 +163,14 @@ reusing stale cached connections."
       (if (or (and (eq? key 'system-error)
                    (= EPIPE (system-error-errno `(,key ,@args))))
               (and (eq? key 'gnutls-error)
-                   (eq? (first args) error/invalid-session))
+                   (memq (first args)
+                         (list error/invalid-session
+
+                               ;; XXX: These two are not properly handled in
+                               ;; GnuTLS < 3.7.2, in
+                               ;; 'write_to_session_record_port'; see
+                               ;; <https://bugs.gnu.org/47867>.
+                               error/again error/interrupted)))
               (memq key
                     '(bad-response bad-header bad-header-component)))
           #f
@@ -207,15 +214,14 @@ returning."
         ;; Inherit the HTTP proxying property from P.
         (set-http-proxy-port?! buffer (http-proxy-port? p))
 
-        (unless (false-if-networking-error
-                 (begin
-                   (for-each (cut write-request <> buffer) batch)
-                   (put-bytevector p (get))
-                   (force-output p)
-                   #t))
-          ;; If PORT becomes unusable, open a fresh connection and retry.
-          (close-port p)                          ; close the broken port
-          (connect #f requests result)))
+        ;; Swallow networking errors that could occur due to connection reuse
+        ;; and the like; they will be handled down the road when trying to
+        ;; read responses.
+        (false-if-networking-error
+         (begin
+           (for-each (cut write-request <> buffer) batch)
+           (put-bytevector p (get))
+           (force-output p))))
 
       ;; Now start processing responses.
       (let loop ((sent      batch)
diff --git a/guix/import/go.scm b/guix/import/go.scm
index bc53f8f558..d110954664 100644
--- a/guix/import/go.scm
+++ b/guix/import/go.scm
@@ -33,7 +33,7 @@
   #:use-module (guix http-client)
   #:use-module ((guix licenses) #:prefix license:)
   #:use-module (guix memoization)
-  #:use-module (htmlprag)               ;from Guile-Lib
+  #:autoload   (htmlprag) (html->sxml)            ;from Guile-Lib
   #:autoload   (guix git) (update-cached-checkout)
   #:autoload   (gcrypt hash) (open-hash-port hash-algorithm sha256)
   #:autoload   (guix serialization) (write-file)
@@ -63,9 +63,6 @@
   #:export (go-module->guix-package
             go-module-recursive-import))
 
-;;; Parameterize htmlprag to parse valid HTML more reliably.
-(%strict-tokenizer? #t)
-
 ;;; Commentary:
 ;;;
 ;;; (guix import go) attempts to make it easier to create Guix package
@@ -149,7 +146,7 @@ name (e.g. \"github.com/golang/protobuf/proto\")."
          ;; element marked with a "License" class attribute.
          (select (sxpath `(// (* (@ (equal? (class "License"))))
                               h2 // *text*))))
-    (select (html->sxml body))))
+    (select (html->sxml body #:strict? #t))))
 
 (define (sxml->texi sxml-node)
   "A very basic SXML to Texinfo converter which attempts to preserve HTML
@@ -167,7 +164,7 @@ formatting and links as text."
   "Retrieve a short description for NAME, a Go package name,
 e.g. \"google.golang.org/protobuf/proto\"."
   (let* ((body (go.pkg.dev-info name))
-         (sxml (html->sxml body))
+         (sxml (html->sxml body #:strict? #t))
          (overview ((sxpath
                      `(//
                        (* (@ (equal? (class "Documentation-overview"))))
@@ -209,7 +206,7 @@ the https://pkg.go.dev/ web site."
          (select-title (sxpath
                         `(// (div (@ (equal? (class "UnitReadme-content"))))
                              // h3 *text*))))
-    (match (select-title (html->sxml body))
+    (match (select-title (html->sxml body #:strict? #t))
       (() #f)                           ;nothing selected
       ((title more ...)                 ;title is the first string of the list
        (string-trim-both title)))))
@@ -465,7 +462,7 @@ build a package."
   (let* ((meta-data (http-fetch* (format #f "https://~a?go-get=1" module-path)))
          (select (sxpath `(// head (meta (@ (equal? (name "go-import"))))
                               // content))))
-    (match (select (html->sxml meta-data))
+    (match (select (html->sxml meta-data #:strict? #t))
       (() #f)                           ;nothing selected
       (((content content-text))
        (match (string-split content-text #\space)
diff --git a/guix/import/pypi.scm b/guix/import/pypi.scm
index bf4dc50138..6731d50891 100644
--- a/guix/import/pypi.scm
+++ b/guix/import/pypi.scm
@@ -229,8 +229,8 @@ the input field."
        '("test" "dev")))
 
 (define (parse-requires.txt requires.txt)
-  "Given REQUIRES.TXT, a Setuptools requires.txt file, return a list of lists
-of requirements.
+  "Given REQUIRES.TXT, a path to a Setuptools requires.txt file, return a list
+of lists of requirements.
 
 The first list contains the required dependencies while the second the
 optional test dependencies.  Note that currently, optional, non-test
diff --git a/guix/import/snix.scm b/guix/import/snix.scm
deleted file mode 100644
index 56934e8cf9..0000000000
--- a/guix/import/snix.scm
+++ /dev/null
@@ -1,467 +0,0 @@
-;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
-;;;
-;;; This file is part of GNU Guix.
-;;;
-;;; GNU Guix is free software; you can redistribute it and/or modify it
-;;; under the terms of the GNU General Public License as published by
-;;; the Free Software Foundation; either version 3 of the License, or (at
-;;; your option) any later version.
-;;;
-;;; GNU Guix is distributed in the hope that it will be useful, but
-;;; WITHOUT ANY WARRANTY; without even the implied warranty of
-;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-;;; GNU General Public License for more details.
-;;;
-;;; You should have received a copy of the GNU General Public License
-;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
-
-(define-module (guix import snix)
-  #:use-module (sxml ssax)
-  #:use-module (ice-9 popen)
-  #:use-module (ice-9 match)
-  #:use-module (ice-9 rdelim)
-  #:use-module (ice-9 format)
-  #:use-module (ice-9 regex)
-  #:use-module (ice-9 vlist)
-  #:use-module (srfi srfi-1)
-  #:use-module (srfi srfi-9)
-  #:use-module (srfi srfi-11)
-  #:use-module (srfi srfi-26)
-  #:use-module (srfi srfi-37)
-  #:use-module (system foreign)
-  #:use-module (rnrs bytevectors)
-
-  ;; Use the 'package-name->name+version' procedure that works with
-  ;; hyphen-separate name/version, not the one that works with '@'-separated
-  ;; name/version.  Subtle!
-  #:use-module ((guix utils) #:hide (package-name->name+version))
-  #:use-module ((guix build utils) #:select (package-name->name+version))
-
-  #:use-module (guix import utils)
-  #:use-module (guix base16)
-  #:use-module (guix base32)
-  #:use-module (guix config)
-  #:use-module (guix gnu-maintenance)
-  #:export (open-nixpkgs
-            xml->snix
-            nixpkgs->guix-package))
-
-;;; Commentary:
-;;;
-;;; Converting Nix code to s-expressions, and then to Guix `package'
-;;; declarations, using the XML output of `nix-instantiate'.
-;;;
-;;; Code:
-
-
-;;;
-;;; SNix.
-;;;
-
-;; Nix object types visible in the XML output of `nix-instantiate' and
-;; mapping to S-expressions (we map to sexps, not records, so that we
-;; can do pattern matching):
-;;
-;;   at               (at varpat attrspat)
-;;   attr             (attribute loc name value)
-;;   attrs            (attribute-set attributes)
-;;   attrspat         (attribute-set-pattern patterns)
-;;   bool             #f|#t
-;;   derivation       (derivation drv-path out-path attributes)
-;;   ellipsis         '...
-;;   expr             (snix loc body ...)
-;;   function         (function loc at|attrspat|varpat)
-;;   int              int
-;;   list             list
-;;   null             'null
-;;   path             string
-;;   string           string
-;;   unevaluated      'unevaluated
-;;   varpat           (varpat name)
-;;
-;; Initially ATTRIBUTES in `derivation' and `attribute-set' was a promise;
-;; however, handling `repeated' nodes makes it impossible to do anything
-;; lazily because the whole SXML tree has to be traversed to maintain the
-;; list of known derivations.
-
-(define (xml-element->snix elem attributes body derivations)
-  "Return an SNix element corresponding to XML element ELEM."
-
-  (define (loc)
-    (location (assq-ref attributes 'path)
-              (assq-ref attributes 'line)
-              (assq-ref attributes 'column)))
-
-  (case elem
-    ((at)
-     (values `(at ,(car body) ,(cadr body)) derivations))
-    ((attr)
-     (let ((name (assq-ref attributes 'name)))
-       (cond ((null? body)
-              (values `(attribute-pattern ,name) derivations))
-             ((and (pair? body) (null? (cdr body)))
-              (values `(attribute ,(loc) ,name ,(car body))
-                      derivations))
-             (else
-              (error "invalid attribute body" name (loc) body)))))
-    ((attrs)
-     (values `(attribute-set ,(reverse body)) derivations))
-    ((attrspat)
-     (values `(attribute-set-pattern ,body) derivations))
-    ((bool)
-     (values (string-ci=? "true" (assq-ref attributes 'value))
-             derivations))
-    ((derivation)
-     (let ((drv-path (assq-ref attributes 'drvPath))
-           (out-path (assq-ref attributes 'outPath)))
-       (if (equal? body '(repeated))
-           (let ((body (vhash-assoc drv-path derivations)))
-             (if (pair? body)
-                 (values `(derivation ,drv-path ,out-path ,(cdr body))
-                         derivations)
-
-                 ;; DRV-PATH hasn't been encountered yet but may be later
-                 ;; (see <http://article.gmane.org/gmane.linux.distributions.nixos/5946>.)
-                 ;; Return an `unresolved' node.
-                 (values `(unresolved
-                           ,(lambda (derivations)
-                              (let ((body (vhash-assoc drv-path derivations)))
-                                (if (pair? body)
-                                    `(derivation ,drv-path ,out-path
-                                                 ,(cdr body))
-                                    (error "no previous occurrence of derivation"
-                                           drv-path)))))
-                         derivations)))
-           (values `(derivation ,drv-path ,out-path ,body)
-                   (vhash-cons drv-path body derivations)))))
-    ((ellipsis)
-     (values '... derivations))
-    ((expr)
-     (values `(snix ,(loc) ,@body) derivations))
-    ((function)
-     (values `(function ,(loc) ,body) derivations))
-    ((int)
-     (values (string->number (assq-ref attributes 'value))
-             derivations))
-    ((list)
-     (values body derivations))
-    ((null)
-     (values 'null derivations))
-    ((path)
-     (values (assq-ref attributes 'value) derivations))
-    ((repeated)
-     (values 'repeated derivations))
-    ((string)
-     (values (assq-ref attributes 'value) derivations))
-    ((unevaluated)
-     (values 'unevaluated derivations))
-    ((varpat)
-     (values `(varpat ,(assq-ref attributes 'name)) derivations))
-    (else (error "unhandled Nix XML element" elem))))
-
-(define (resolve snix derivations)
-  "Return a new SNix tree where `unresolved' nodes from SNIX have been
-replaced by the result of their application to DERIVATIONS, a vhash."
-  (let loop ((node snix)
-             (seen vlist-null))
-    (if (vhash-assq node seen)
-        (values node seen)
-        (match node
-          (('unresolved proc)
-           (let ((n (proc derivations)))
-             (values n seen)))
-          ((tag body ...)
-           (let ((body+seen (fold (lambda (n body+seen)
-                                    (call-with-values
-                                        (lambda ()
-                                          (loop n (cdr body+seen)))
-                                      (lambda (n* seen)
-                                        (cons (cons n* (car body+seen))
-                                              (vhash-consq n #t seen)))))
-                                  (cons '() (vhash-consq node #t seen))
-                                  body)))
-             (values (cons tag (reverse (car body+seen)))
-                     (vhash-consq node #t (cdr body+seen)))))
-          (anything
-           (values anything seen))))))
-
-(define xml->snix
-  (let ((parse
-         (ssax:make-parser NEW-LEVEL-SEED
-                           (lambda (elem-gi attributes namespaces expected-content
-                                    seed)
-                             (cons '() (cdr seed)))
-
-                           FINISH-ELEMENT
-                           (lambda (elem-gi attributes namespaces parent-seed
-                                            seed)
-                             (let ((snix        (car seed))
-                                   (derivations (cdr seed)))
-                               (let-values (((snix derivations)
-                                             (xml-element->snix elem-gi
-                                                                attributes
-                                                                snix
-                                                                derivations)))
-                                 (cons (cons snix (car parent-seed))
-                                       derivations))))
-
-                           CHAR-DATA-HANDLER
-                           (lambda (string1 string2 seed)
-                             ;; Discard inter-node strings, which are blanks.
-                             seed))))
-    (lambda (port)
-      "Return the SNix represention of TREE, an SXML tree as returned by
-parsing the XML output of `nix-instantiate' on Nixpkgs."
-      (match (parse port (cons '() vlist-null))
-        (((snix) . derivations)
-         (resolve snix derivations))))))
-
-(define (attribute-value attribute)
-  "Return the value of ATTRIBUTE."
-  (match attribute
-    (('attribute _ _ value) value)))
-
-(define (derivation-source derivation)
-  "Return the \"src\" attribute of DERIVATION or #f if not found."
-  (match derivation
-    (('derivation _ _ (attributes ...))
-     (find-attribute-by-name "src" attributes))))
-
-(define (derivation-output-path derivation)
-  "Return the output path of DERIVATION."
-  (match derivation
-    (('derivation _ out-path _)
-     out-path)
-    (_ #f)))
-
-(define (source-output-path src)
-  "Return the output path of SRC, the \"src\" attribute of a derivation."
-  (derivation-output-path (attribute-value src)))
-
-(define (source-urls src)
-  "Return the URLs of SRC, the \"src\" attribute of a derivation."
-  (match src
-    (('attribute _ _ ('derivation _ _ (attributes ...)))
-     (match (find-attribute-by-name "urls" attributes)
-       (('attribute _ _ value)
-        value)))
-    (_ #f)))
-
-(define (source-sha256 src)
-  "Return the sha256 of SRC, the \"src\" attribute of a derivation, as a
-bytevector."
-  (match src
-    (('attribute _ _ ('derivation _ _ (attributes ...)))
-     (match (find-attribute-by-name "outputHash" attributes)
-       (('attribute _ _ value)
-        (match value
-          ((= string-length 52)
-           (nix-base32-string->bytevector value))
-          ((= string-length 64)
-           (base16-string->bytevector value))
-          (_
-           (error "unsupported hash format" value))))))
-    (_ #f)))
-
-(define (derivation-source-output-path derivation)
-  "Return the output path of the \"src\" attribute of DERIVATION or #f
-if DERIVATION lacks an \"src\" attribute."
-  (and=> (derivation-source derivation) source-output-path))
-
-(define* (open-nixpkgs nixpkgs #:optional attribute)
-  "Return an input pipe to the XML representation of Nixpkgs.  When
-ATTRIBUTE is true, only that attribute is considered."
-  (with-fluids ((%default-port-encoding "UTF-8"))
-    (let ((cross-system (format #f "{
-  config = \"i686-guix-linux-gnu\";
-  libc = \"glibc\";
-  arch = \"guix\";
-  withTLS = true;
-  float = \"hard\";
-  openssl.system = \"linux-generic32\";
-  platform = (import ~a/pkgs/top-level/platforms.nix).sheevaplug;
-}" nixpkgs)))
-      (apply open-pipe* OPEN_READ
-             "nix-instantiate" "--strict" "--eval-only" "--xml"
-
-             ;; Pass a dummy `crossSystem' argument so that `buildInputs' and
-             ;; `nativeBuildInputs' are not coalesced.
-             ;; XXX: This is hacky and has other problems.
-             ;"--arg" "crossSystem" cross-system
-
-             `(,@(if attribute
-                     `("-A" ,attribute)
-                     '())
-               ,nixpkgs)))))
-
-(define (pipe-failed? pipe)
-  "Close pipe and return its status if it failed."
-  (let ((status (close-pipe pipe)))
-    (if (or (status:term-sig status)
-            (not (= (status:exit-val status) 0)))
-        status
-        #f)))
-
-(define (find-attribute-by-name name attributes)
-  "Return attribute NAME in ATTRIBUTES, an attribute set or list of SNix
-attributes, or #f if NAME cannot be found."
-  (find (lambda (a)
-          (match a
-            (('attribute _ (? (cut string=? <> name)) _)
-             a)
-            (_ #f)))
-        (match attributes
-          (('attribute-set (attributes ...))
-           attributes)
-          (_
-           attributes))))
-
-(define (license-variable license)
-  "Return the name of the (guix licenses) variable for LICENSE."
-  (match license
-    ("GPLv2+"    'gpl2+)
-    ("GPLv3+"    'gpl3+)
-    ("LGPLv2+"   'lgpl2.1+)
-    ("LGPLv2.1+" 'lgpl2.1+)
-    ("LGPLv3+"   'lgpl3+)
-    (('attribute-set _ ...)
-     ;; At some point in 2013, Nixpkgs switched to attribute sets to represent
-     ;; licenses.  These are listed in lib/licenses.nix.
-     (match (and=> (find-attribute-by-name "shortName" license)
-                   attribute-value)
-       ("agpl3Plus"  'agpl3+)
-       ("gpl2Plus"   'gpl2+)
-       ("gpl3Plus"   'gpl3+)
-       ("lgpl2Plus"  'lgpl2.0+)
-       ("lgpl21Plus" 'lgpl2.1+)
-       ("lgpl3Plus"  'lgpl3+)
-       ((? string? x) x)
-       (_             license)))
-    (_           license)))
-
-(define (package-source-output-path package)
-  "Return the output path of the \"src\" derivation of PACKAGE."
-  (derivation-source-output-path (attribute-value package)))
-
-
-;;;
-;;; Conversion of "Nix expressions" to "Guix expressions".
-;;;
-
-(define (snix-derivation->guix-package derivation)
-  "Return the `package' s-expression corresponding to SNix DERIVATION, a
-Nixpkgs `stdenv.mkDerivation'-style derivation, and the original source
-location of DERIVATION."
-  (match derivation
-    (('derivation _ _ (attributes ...))
-     (let*-values (((full-name loc)
-                    (match (find-attribute-by-name "name" attributes)
-                      (('attribute loc _ value)
-                       (values value loc))
-                      (_
-                       (values #f #f))))
-                   ((name version)
-                    (package-name->name+version full-name)))
-       (define (convert-inputs type)
-         ;; Convert the derivation's input from a list of SNix derivations to
-         ;; a list of name/variable pairs.
-         (match (and=> (find-attribute-by-name type attributes)
-                       attribute-value)
-           (#f
-            '())
-           ((inputs ...)
-            ;; Inputs can be either derivations or the null value.
-            (filter-map (match-lambda
-                         (('derivation _ _ (attributes ...))
-                          (let* ((full-name
-                                  (attribute-value
-                                   (find-attribute-by-name "name" attributes)))
-                                 (name (package-name->name+version full-name)))
-                            (list name
-                                  (list 'unquote (string->symbol name)))))
-                         ('null #f))
-                        inputs))))
-
-       (define (maybe-inputs guix-name inputs)
-         (match inputs
-           (()
-            '())
-           ((inputs ...)
-            (list (list guix-name
-                        (list 'quasiquote inputs))))))
-
-       (define (pretty-uri uri version)
-         (if version
-             (match (factorize-uri uri version)
-               ((items ...)
-                `(string-append ,@items))
-               (x x))
-             uri))
-
-       (let* ((source  (find-attribute-by-name "src" attributes))
-              (urls    (source-urls source))
-              (sha256  (source-sha256 source))
-              (meta    (and=> (find-attribute-by-name "meta" attributes)
-                              attribute-value)))
-         (values
-          `(package
-             (name ,name)
-             (version ,version)
-             (source (origin
-                      (method url-fetch)
-                      (uri ,(pretty-uri (car urls) version))
-                      (sha256
-                       (base32
-                        ,(bytevector->nix-base32-string sha256)))))
-             (build-system gnu-build-system)
-
-             ;; When doing a native Nixpkgs build, `buildInputs' is empty and
-             ;; everything is in `nativeBuildInputs'.  So we can't distinguish
-             ;; between both, here.
-             ;;
-             ;; Note that `nativeBuildInputs' was renamed from
-             ;; `buildNativeInputs' in Nixpkgs sometime around March 2013.
-             ,@(maybe-inputs 'inputs
-                             (convert-inputs "nativeBuildInputs"))
-             ,@(maybe-inputs 'propagated-inputs
-                             (convert-inputs "propagatedNativeBuildInputs"))
-
-             (home-page ,(and=> (find-attribute-by-name "homepage" meta)
-                                attribute-value))
-             (synopsis
-              ;; For GNU packages, prefer the official synopsis.
-              ,(or (false-if-exception
-                    (and=> (find (lambda (gnu-package)
-                                   (equal? (gnu-package-name gnu-package)
-                                           name))
-                                 (official-gnu-packages))
-                           gnu-package-doc-summary))
-                   (and=> (find-attribute-by-name "description" meta)
-                          attribute-value)))
-             (description
-              ;; Likewise, prefer the official description of GNU packages.
-              ,(or (false-if-exception
-                    (and=> (find (lambda (gnu-package)
-                                   (equal? (gnu-package-name gnu-package)
-                                           name))
-                                 (official-gnu-packages))
-                           gnu-package-doc-description))
-                   (and=> (find-attribute-by-name "longDescription" meta)
-                          attribute-value)))
-             (license ,(and=> (find-attribute-by-name "license" meta)
-                              (compose license-variable attribute-value))))
-          loc))))))
-
-(define (nixpkgs->guix-package nixpkgs attribute)
-  "Evaluate ATTRIBUTE in NIXPKGS, the file name of a Nixpkgs checkout,
-and return the `package' s-expression corresponding to that package."
-  (let ((port (open-nixpkgs nixpkgs attribute)))
-    (match (xml->snix port)
-      (('snix loc (and drv ('derivation _ ...)))
-       (and (not (pipe-failed? port))
-            (snix-derivation->guix-package drv)))
-      (_
-       (not (pipe-failed? port))))))
-
-;;; snix.scm ends here
diff --git a/guix/lint.scm b/guix/lint.scm
index a7d6bbba4f..1bebfe03d3 100644
--- a/guix/lint.scm
+++ b/guix/lint.scm
@@ -11,6 +11,7 @@
 ;;; Copyright © 2018, 2019 Arun Isaac <arunisaac@systemreboot.net>
 ;;; Copyright © 2020 Chris Marusich <cmmarusich@gmail.com>
 ;;; Copyright © 2020 Timothy Sample <samplet@ngyro.com>
+;;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -81,6 +82,7 @@
             check-synopsis-style
             check-derivation
             check-home-page
+            check-name
             check-source
             check-source-file-name
             check-source-unstable-tarball
@@ -173,14 +175,20 @@
 (define (check-name package)
   "Check whether PACKAGE's name matches our guidelines."
   (let ((name (package-name package)))
-    ;; Currently checks only whether the name is too short.
-    (if (and (<= (string-length name) 1)
-             (not (string=? name "r"))) ; common-sense exception
-        (list
-         (make-warning package
-                       (G_ "name should be longer than a single character")
-                       #:field 'name))
-        '())))
+    (cond
+     ;; Currently checks only whether the name is too short.
+     ((and (<= (string-length name) 1)
+           (not (string=? name "r"))) ; common-sense exception
+      (list
+       (make-warning package
+                     (G_ "name should be longer than a single character")
+                     #:field 'name)))
+     ((string-index name #\_)
+      (list
+       (make-warning package
+                     (G_ "name should use hyphens instead of underscores")
+                     #:field 'name)))
+     (else '()))))
 
 (define (properly-starts-sentence? s)
   (string-match "^[(\"'`[:upper:][:digit:]]" s))
diff --git a/guix/packages.scm b/guix/packages.scm
index 3ae205b22a..ba19174646 100644
--- a/guix/packages.scm
+++ b/guix/packages.scm
@@ -807,7 +807,8 @@ specifies modules in scope when evaluating SNIPPET."
   "Return package ORIGINAL with PATCHES applied."
   (package (inherit original)
            (source (origin (inherit (package-source original))
-                           (patches patches)))))
+                           (patches patches)))
+           (location (package-location original))))
 
 (define (package-with-extra-patches original patches)
   "Return package ORIGINAL with all PATCHES appended to its list of patches."
diff --git a/guix/profiles.scm b/guix/profiles.scm
index 7a207589b0..2ec78b080a 100644
--- a/guix/profiles.scm
+++ b/guix/profiles.scm
@@ -4,7 +4,7 @@
 ;;; Copyright © 2014, 2016 Alex Kost <alezost@gmail.com>
 ;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
 ;;; Copyright © 2015 Sou Bunnbu <iyzsong@gmail.com>
-;;; Copyright © 2016, 2018, 2019 Ricardo Wurmus <rekado@elephly.net>
+;;; Copyright © 2016, 2018, 2019, 2021 Ricardo Wurmus <rekado@elephly.net>
 ;;; Copyright © 2016 Chris Marusich <cmmarusich@gmail.com>
 ;;; Copyright © 2017 Huang Ying <huang.ying.caritas@gmail.com>
 ;;; Copyright © 2017 Maxim Cournoyer <maxim.cournoyer@gmail.com>
@@ -1115,6 +1115,46 @@ MANIFEST.  Single-file bundles are required by programs such as Git and Lynx."
                     `((type . profile-hook)
                       (hook . ca-certificate-bundle))))
 
+(define (emacs-subdirs manifest)
+  (define build
+    (with-imported-modules (source-module-closure
+                            '((guix build profiles)
+                              (guix build utils)))
+      #~(begin
+          (use-modules (guix build utils)
+                       (guix build profiles)
+                       (ice-9 ftw) ; scandir
+                       (srfi srfi-1) ; append-map
+                       (srfi srfi-26))
+
+          (let ((destdir (string-append #$output "/share/emacs/site-lisp"))
+                (subdirs
+                 (append-map
+                  (lambda (dir)
+                    (filter
+                     file-is-directory?
+                     (map (cute string-append dir "/" <>)
+                          (scandir dir (negate (cute member <> '("." "..")))))))
+                  (filter file-exists?
+                          (map (cute string-append <> "/share/emacs/site-lisp")
+                               '#$(manifest-inputs manifest))))))
+            (mkdir-p destdir)
+            (with-directory-excursion destdir
+              (call-with-output-file "subdirs.el"
+                (lambda (port)
+                  (write
+                   `(normal-top-level-add-to-load-path
+                     (list ,@subdirs))
+                   port)
+                  (newline port)
+                  #t)))))))
+  (gexp->derivation "emacs-subdirs" build
+                    #:local-build? #t
+                    #:substitutable? #f
+                    #:properties
+                    `((type . profile-hook)
+                      (hook . emacs-subdirs))))
+
 (define (glib-schemas manifest)
   "Return a derivation that unions all schemas from manifest entries and
 creates the Glib 'gschemas.compiled' file."
@@ -1625,6 +1665,7 @@ the entries in MANIFEST."
         fonts-dir-file
         ghc-package-cache-file
         ca-certificate-bundle
+        emacs-subdirs
         glib-schemas
         gtk-icon-themes
         gtk-im-modules
diff --git a/guix/scripts/import.scm b/guix/scripts/import.scm
index 98554ef79b..bbd9a3b190 100644
--- a/guix/scripts/import.scm
+++ b/guix/scripts/import.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2012, 2013, 2014, 2020 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2012, 2013, 2014, 2020, 2021 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2014 David Thompson <davet@gnu.org>
 ;;; Copyright © 2018 Kyle Meyer <kyle@kyleam.com>
 ;;; Copyright © 2019 Ricardo Wurmus <rekado@elephly.net>
@@ -76,7 +76,7 @@ rather than \\n."
 ;;; Entry point.
 ;;;
 
-(define importers '("gnu" "nix" "pypi" "cpan" "hackage" "stackage" "elpa" "gem"
+(define importers '("gnu" "pypi" "cpan" "hackage" "stackage" "elpa" "gem"
                     "go" "cran" "crate" "texlive" "json" "opam"))
 
 (define (resolve-importer name)
diff --git a/guix/scripts/import/nix.scm b/guix/scripts/import/nix.scm
deleted file mode 100644
index 45ca7e3fcf..0000000000
--- a/guix/scripts/import/nix.scm
+++ /dev/null
@@ -1,90 +0,0 @@
-;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2012, 2013, 2016 Ludovic Courtès <ludo@gnu.org>
-;;; Copyright © 2014 David Thompson <davet@gnu.org>
-;;;
-;;; This file is part of GNU Guix.
-;;;
-;;; GNU Guix is free software; you can redistribute it and/or modify it
-;;; under the terms of the GNU General Public License as published by
-;;; the Free Software Foundation; either version 3 of the License, or (at
-;;; your option) any later version.
-;;;
-;;; GNU Guix is distributed in the hope that it will be useful, but
-;;; WITHOUT ANY WARRANTY; without even the implied warranty of
-;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-;;; GNU General Public License for more details.
-;;;
-;;; You should have received a copy of the GNU General Public License
-;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
-
-(define-module (guix scripts import nix)
-  #:use-module (guix ui)
-  #:use-module (guix utils)
-  #:use-module (guix scripts)
-  #:use-module (guix import snix)
-  #:use-module (guix scripts import)
-  #:use-module (srfi srfi-1)
-  #:use-module (srfi srfi-11)
-  #:use-module (srfi srfi-37)
-  #:use-module (ice-9 match)
-  #:export (guix-import-nix))
-
-
-;;;
-;;; Command-line options.
-;;;
-
-(define %default-options
-  '())
-
-(define (show-help)
-  (display (G_ "Usage: guix import nix NIXPKGS ATTRIBUTE
-Import and convert the Nix expression ATTRIBUTE of NIXPKGS.\n"))
-  (display (G_ "
-  -h, --help             display this help and exit"))
-  (display (G_ "
-  -V, --version          display version information and exit"))
-  (newline)
-  (show-bug-report-information))
-
-(define %options
-  ;; Specification of the command-line options.
-  (cons* (option '(#\h "help") #f #f
-                 (lambda args
-                   (show-help)
-                   (exit 0)))
-         (option '(#\V "version") #f #f
-                 (lambda args
-                   (show-version-and-exit "guix import nix")))
-         %standard-import-options))
-
-
-;;;
-;;; Entry point.
-;;;
-
-(define (guix-import-nix . args)
-  (define (parse-options)
-    ;; Return the alist of option values.
-    (args-fold* args %options
-                (lambda (opt name arg result)
-                  (leave (G_ "~A: unrecognized option~%") name))
-                (lambda (arg result)
-                  (alist-cons 'argument arg result))
-                %default-options))
-
-  (let* ((opts (parse-options))
-         (args (filter-map (match-lambda
-                            (('argument . value)
-                             value)
-                            (_ #f))
-                           (reverse opts))))
-    (match args
-      ((nixpkgs attribute)
-       (let-values (((expr loc)
-                     (nixpkgs->guix-package nixpkgs attribute)))
-         (format #t ";; converted from ~a:~a~%~%"
-                 (location-file loc) (location-line loc))
-         expr))
-      (x
-       (leave (G_ "wrong number of arguments~%"))))))
diff --git a/guix/scripts/perform-download.scm b/guix/scripts/perform-download.scm
index 8d409092ba..6889bcef79 100644
--- a/guix/scripts/perform-download.scm
+++ b/guix/scripts/perform-download.scm
@@ -54,7 +54,8 @@ actual output is different from that when we're doing a 'bmCheck' or
                        (output* "out")
                        (executable "executable")
                        (mirrors "mirrors")
-                       (content-addressed-mirrors "content-addressed-mirrors"))
+                       (content-addressed-mirrors "content-addressed-mirrors")
+                       (disarchive-mirrors "disarchive-mirrors"))
     (unless url
       (leave (G_ "~a: missing URL~%") (derivation-file-name drv)))
 
@@ -79,6 +80,10 @@ actual output is different from that when we're doing a 'bmCheck' or
                              (lambda (port)
                                (eval (read port) %user-module)))
                            '())
+                       #:disarchive-mirrors
+                       (if disarchive-mirrors
+                           (call-with-input-file disarchive-mirrors read)
+                           '())
                        #:hashes `((,algo . ,hash))
 
                        ;; Since DRV's output hash is known, X.509 certificate
diff --git a/guix/scripts/substitute.scm b/guix/scripts/substitute.scm
index 48309f9b3a..8e4eae00b3 100755
--- a/guix/scripts/substitute.scm
+++ b/guix/scripts/substitute.scm
@@ -45,7 +45,7 @@
                 #:select (uri-abbreviation nar-uri-abbreviation
                           (open-connection-for-uri
                            . guix:open-connection-for-uri)))
-  #:autoload   (gnutls) (error/invalid-session)
+  #:autoload   (gnutls) (error/invalid-session error/again error/interrupted)
   #:use-module (guix progress)
   #:use-module ((guix build syscalls)
                 #:select (set-thread-name))
@@ -417,7 +417,14 @@ server certificates."
         (if (or (and (eq? key 'system-error)
                      (= EPIPE (system-error-errno `(,key ,@args))))
                 (and (eq? key 'gnutls-error)
-                     (eq? (first args) error/invalid-session))
+                     (memq (first args)
+                           (list error/invalid-session
+
+                                 ;; XXX: These two are not properly handled in
+                                 ;; GnuTLS < 3.7.2, in
+                                 ;; 'write_to_session_record_port'; see
+                                 ;; <https://bugs.gnu.org/47867>.
+                                 error/again error/interrupted)))
                 (memq key '(bad-response bad-header bad-header-component)))
             (proc (open-connection-for-uri/cached uri
                                                   #:verify-certificate? #f
diff --git a/guix/scripts/weather.scm b/guix/scripts/weather.scm
index 5164fe0494..6d925d416c 100644
--- a/guix/scripts/weather.scm
+++ b/guix/scripts/weather.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2017, 2018, 2019, 2020, 2021 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2017 Ricardo Wurmus <rekado@elephly.net>
 ;;; Copyright © 2018 Kyle Meyer <kyle@kyleam.com>
 ;;; Copyright © 2020 Simon Tournier <zimon.toutoune@gmail.com>
@@ -171,6 +171,16 @@ about the derivations queued, as is the case with Hydra."
       #f                                          ;no derivation information
       (lset-intersection string=? queued items)))
 
+(define (store-item-system store item)
+  "Return the system (a string such as \"aarch64-linux\")) ITEM targets,
+or #f if it could not be determined."
+  (match (valid-derivers store item)
+    ((drv . _)
+     (and=> (false-if-exception (read-derivation-from-file drv))
+            derivation-system))
+    (()
+     #f)))
+
 (define* (report-server-coverage server items
                                  #:key display-missing?)
   "Report the subset of ITEMS available as substitutes on SERVER.
@@ -270,7 +280,22 @@ are queued~%")
       (when (and display-missing? (not (null? missing)))
         (newline)
         (format #t (G_ "Substitutes are missing for the following items:~%"))
-        (format #t "~{  ~a~%~}" missing))
+
+        ;; Display two columns: store items, and their system type.
+        (format #t "~:{  ~a ~a~%~}"
+                (zip (map (let ((width (max (- (current-terminal-columns)
+                                               20)
+                                            0)))
+                            (lambda (item)
+                              (if (> (string-length item) width)
+                                  item
+                                  (string-pad-right item width))))
+                          missing)
+                     (with-store store
+                       (map (lambda (item)
+                              (or (store-item-system store item)
+                                  (G_ "unknown system")))
+                            missing)))))
 
       ;; Return the coverage ratio.
       (let ((total (length items)))
diff --git a/guix/self.scm b/guix/self.scm
index ec8b6c33cc..cdbb606a0b 100644
--- a/guix/self.scm
+++ b/guix/self.scm
@@ -878,7 +878,8 @@ itself."
                    ("guix/store/schema.sql"
                     ,(local-file "../guix/store/schema.sql")))
 
-                 #:extensions (list guile-gcrypt)
+                 #:extensions (list guile-gcrypt
+                                    guile-json)   ;for (guix swh)
                  #:guile-for-build guile-for-build))
 
   (define *extra-modules*
diff --git a/guix/ssh.scm b/guix/ssh.scm
index 457d1890f9..77a9732ce5 100644
--- a/guix/ssh.scm
+++ b/guix/ssh.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2016, 2017, 2018, 2019, 2020, 2021, 2021 Ludovic Courtès <ludo@gnu.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -253,7 +253,22 @@ EXP never returns or calls 'primitive-exit' when it's done."
        (use-modules (ice-9 match) (rnrs io ports)
                     (rnrs bytevectors))
 
-       (let ((sock    (socket AF_UNIX SOCK_STREAM 0))
+       (define connect-to-daemon
+         ;; XXX: 'connect-to-daemon' used to be private and before that it
+         ;; didn't even exist, hence these shenanigans.
+         (let ((connect-to-daemon
+                (false-if-exception (module-ref (resolve-module '(guix store))
+                                                'connect-to-daemon))))
+           (lambda (uri)
+             (if connect-to-daemon
+                 (connect-to-daemon uri)
+                 (let ((sock (socket AF_UNIX SOCK_STREAM 0)))
+                   (connect sock AF_UNIX ,socket-name)
+                   sock)))))
+
+       ;; Use 'connect-to-daemon' to honor GUIX_DAEMON_SOCKET.
+       (let ((sock    (connect-to-daemon (or (getenv "GUIX_DAEMON_SOCKET")
+                                             socket-name)))
              (stdin   (current-input-port))
              (stdout  (current-output-port))
              (select* (lambda (read write except)
@@ -272,8 +287,6 @@ EXP never returns or calls 'primitive-exit' when it's done."
          (setvbuf stdin 'block 65536)
          (setvbuf sock 'block 65536)
 
-         (connect sock AF_UNIX ,socket-name)
-
          (let loop ()
            (match (select* (list stdin sock) '() '())
              ((reads () ())
@@ -302,8 +315,13 @@ EXP never returns or calls 'primitive-exit' when it's done."
                                     "/var/guix/daemon-socket/socket"))
   "Connect to the remote build daemon listening on SOCKET-NAME over SESSION,
 an SSH session.  Return a <store-connection> object."
-  (open-connection #:port (remote-daemon-channel session socket-name)))
-
+  (guard (c ((store-connection-error? c)
+             ;; Raise a more focused error condition.
+             (raise (formatted-message
+                     (G_ "failed to connect over SSH to daemon at '~a', socket ~a")
+                     (session-get session 'host)
+                     socket-name))))
+    (open-connection #:port (remote-daemon-channel session socket-name))))
 
 (define (store-import-channel session)
   "Return an output port to which archives to be exported to SESSION's store
diff --git a/guix/status.scm b/guix/status.scm
index 362ae2882c..1164c2a6e3 100644
--- a/guix/status.scm
+++ b/guix/status.scm
@@ -379,6 +379,8 @@ the current build phase."
      (G_ "building GHC package cache..."))
     ('ca-certificate-bundle
      (G_ "building CA certificate bundle..."))
+    ('emacs-subdirs
+     (G_ "listing Emacs sub-directories..."))
     ('glib-schemas
      (G_ "generating GLib schema cache..."))
     ('gtk-icon-themes
@@ -552,12 +554,16 @@ substitutes being downloaded."
                                        (download-start download)
                                        #:transferred transferred))))))
     (('substituter-succeeded item _ ...)
-     ;; If there are no jobs running, we already reported download completion
-     ;; so there's nothing left to do.
-     (unless (and (zero? (simultaneous-jobs status))
-                  (extended-build-trace-supported?))
-       (format port (success (G_ "substitution of ~a complete")) item)
-       (newline port)))
+     (when (extended-build-trace-supported?)
+       ;; If there are no jobs running, we already reported download completion
+       ;; so there's nothing left to do.
+       (unless (zero? (simultaneous-jobs status))
+         (format port (success (G_ "substitution of ~a complete")) item))
+
+       (when (and print-urls? (zero? (simultaneous-jobs status)))
+         ;; Leave a blank line after the "downloading ..." line and the
+         ;; progress bar (that's three lines in total).
+         (newline port))))
     (('substituter-failed item _ ...)
      (format port (failure (G_ "substitution of ~a failed")) item)
      (newline port))
diff --git a/guix/store.scm b/guix/store.scm
index 37ae6cfedd..9d706ae590 100644
--- a/guix/store.scm
+++ b/guix/store.scm
@@ -90,6 +90,7 @@
             hash-algo
             build-mode
 
+            connect-to-daemon
             open-connection
             port->connection
             close-connection
@@ -501,7 +502,10 @@
 
 (define (connect-to-daemon uri)
   "Connect to the daemon at URI, a string that may be an actual URI or a file
-name."
+name, and return an input/output port.
+
+This is a low-level procedure that does not perform the initial handshake with
+the daemon.  Use 'open-connection' for that."
   (define (not-supported)
     (raise (condition (&store-connection-error
                        (file uri)
@@ -548,13 +552,16 @@ space on the file system so that the garbage collector can still operate,
 should the disk become full.  When CPU-AFFINITY is true, it must be an integer
 corresponding to an OS-level CPU number to which the daemon's worker process
 for this connection will be pinned.  Return a server object."
+  (define (handshake-error)
+    (raise (condition
+            (&store-connection-error (file (or port uri))
+                                     (errno EPROTO))
+            (&message (message "build daemon handshake failed")))))
+
   (guard (c ((nar-error? c)
              ;; One of the 'write-' or 'read-' calls below failed, but this is
              ;; really a connection error.
-             (raise (condition
-                     (&store-connection-error (file (or port uri))
-                                              (errno EPROTO))
-                     (&message (message "build daemon handshake failed"))))))
+             (handshake-error)))
     (let*-values (((port)
                    (or port (connect-to-daemon uri)))
                   ((output flush)
@@ -562,32 +569,35 @@ for this connection will be pinned.  Return a server object."
                                           (make-bytevector 8192))))
       (write-int %worker-magic-1 port)
       (let ((r (read-int port)))
-        (and (= r %worker-magic-2)
-             (let ((v (read-int port)))
-               (and (= (protocol-major %protocol-version)
-                       (protocol-major v))
-                    (begin
-                      (write-int %protocol-version port)
-                      (when (>= (protocol-minor v) 14)
-                        (write-int (if cpu-affinity 1 0) port)
-                        (when cpu-affinity
-                          (write-int cpu-affinity port)))
-                      (when (>= (protocol-minor v) 11)
-                        (write-int (if reserve-space? 1 0) port))
-                      (letrec* ((built-in-builders
-                                 (delay (%built-in-builders conn)))
-                                (conn
-                                 (%make-store-connection port
-                                                         (protocol-major v)
-                                                         (protocol-minor v)
-                                                         output flush
-                                                         (make-hash-table 100)
-                                                         (make-hash-table 100)
-                                                         vlist-null
-                                                         built-in-builders)))
-                        (let loop ((done? (process-stderr conn)))
-                          (or done? (process-stderr conn)))
-                        conn)))))))))
+        (unless (= r %worker-magic-2)
+          (handshake-error))
+
+        (let ((v (read-int port)))
+          (unless (= (protocol-major %protocol-version)
+                     (protocol-major v))
+            (handshake-error))
+
+          (write-int %protocol-version port)
+          (when (>= (protocol-minor v) 14)
+            (write-int (if cpu-affinity 1 0) port)
+            (when cpu-affinity
+              (write-int cpu-affinity port)))
+          (when (>= (protocol-minor v) 11)
+            (write-int (if reserve-space? 1 0) port))
+          (letrec* ((built-in-builders
+                     (delay (%built-in-builders conn)))
+                    (conn
+                     (%make-store-connection port
+                                             (protocol-major v)
+                                             (protocol-minor v)
+                                             output flush
+                                             (make-hash-table 100)
+                                             (make-hash-table 100)
+                                             vlist-null
+                                             built-in-builders)))
+            (let loop ((done? (process-stderr conn)))
+              (or done? (process-stderr conn)))
+            conn))))))
 
 (define* (port->connection port
                            #:key (version %protocol-version))
diff --git a/guix/swh.scm b/guix/swh.scm
index f11b7ea2d5..3005323fd1 100644
--- a/guix/swh.scm
+++ b/guix/swh.scm
@@ -108,6 +108,7 @@
 
             commit-id?
 
+            swh-download-directory
             swh-download))
 
 ;;; Commentary:
@@ -147,12 +148,20 @@
       url
       (string-append url "/")))
 
-;; XXX: Work around a bug in Guile 3.0.2 where #:verify-certificate? would
-;; be ignored (<https://bugs.gnu.org/40486>).
-(define* (http-get* uri #:rest rest)
-  (apply http-request uri #:method 'GET rest))
-(define* (http-post* uri #:rest rest)
-  (apply http-request uri #:method 'POST rest))
+(cond-expand
+  (guile-3
+   ;; XXX: Work around a bug in Guile 3.0.2 where #:verify-certificate? would
+   ;; be ignored (<https://bugs.gnu.org/40486>).
+   (define* (http-get* uri #:rest rest)
+     (apply http-request uri #:method 'GET rest))
+   (define* (http-post* uri #:rest rest)
+     (apply http-request uri #:method 'POST rest)))
+  (else                                           ;Guile 2.2
+   ;; Guile 2.2 did not have #:verify-certificate? so ignore it.
+   (define* (http-get* uri #:key verify-certificate? streaming?)
+     (http-request uri #:method 'GET #:streaming? streaming?))
+   (define* (http-post* uri #:key verify-certificate? streaming?)
+     (http-request uri #:method 'POST #:streaming? streaming?))))
 
 (define %date-regexp
   ;; Match strings like "2014-11-17T22:09:38+01:00" or
@@ -558,12 +567,6 @@ requested bundle cooking, waiting for completion...~%"))
 ;;; High-level interface.
 ;;;
 
-(define (commit-id? reference)
-  "Return true if REFERENCE is likely a commit ID, false otherwise---e.g., if
-it is a tag name.  This is based on a simple heuristic so use with care!"
-  (and (= (string-length reference) 40)
-       (string-every char-set:hex-digit reference)))
-
 (define (call-with-temporary-directory proc)      ;FIXME: factorize
   "Call PROC with a name of a temporary directory; close the directory and
 delete it when leaving the dynamic extent of this call."
@@ -577,6 +580,39 @@ delete it when leaving the dynamic extent of this call."
       (lambda ()
         (false-if-exception (delete-file-recursively tmp-dir))))))
 
+(define* (swh-download-directory id output
+                                 #:key (log-port (current-error-port)))
+  "Download from Software Heritage the directory with the given ID, and
+unpack it to OUTPUT.  Return #t on success and #f on failure"
+  (call-with-temporary-directory
+   (lambda (directory)
+     (match (vault-fetch id 'directory #:log-port log-port)
+       (#f
+        (format log-port
+                "SWH: directory ~a could not be fetched from the vault~%"
+                id)
+        #f)
+       ((? port? input)
+        (let ((tar (open-pipe* OPEN_WRITE "tar" "-C" directory "-xzvf" "-")))
+          (dump-port input tar)
+          (close-port input)
+          (let ((status (close-pipe tar)))
+            (unless (zero? status)
+              (error "tar extraction failure" status)))
+
+          (match (scandir directory)
+            (("." ".." sub-directory)
+             (copy-recursively (string-append directory "/" sub-directory)
+                               output
+                               #:log (%make-void-port "w"))
+             #t))))))))
+
+(define (commit-id? reference)
+  "Return true if REFERENCE is likely a commit ID, false otherwise---e.g., if
+it is a tag name.  This is based on a simple heuristic so use with care!"
+  (and (= (string-length reference) 40)
+       (string-every char-set:hex-digit reference)))
+
 (define* (swh-download url reference output
                        #:key (log-port (current-error-port)))
   "Download from Software Heritage a checkout of the Git tag or commit
@@ -593,28 +629,7 @@ wait until it becomes available, which could take several minutes."
      (format log-port "SWH: found revision ~a with directory at '~a'~%"
              (revision-id revision)
              (swh-url (revision-directory-url revision)))
-     (call-with-temporary-directory
-      (lambda (directory)
-        (match (vault-fetch (revision-directory revision) 'directory
-                            #:log-port log-port)
-          (#f
-           (format log-port
-                   "SWH: directory ~a could not be fetched from the vault~%"
-                   (revision-directory revision))
-           #f)
-          ((? port? input)
-           (let ((tar (open-pipe* OPEN_WRITE "tar" "-C" directory "-xzvf" "-")))
-             (dump-port input tar)
-             (close-port input)
-             (let ((status (close-pipe tar)))
-               (unless (zero? status)
-                 (error "tar extraction failure" status)))
-
-             (match (scandir directory)
-               (("." ".." sub-directory)
-                (copy-recursively (string-append directory "/" sub-directory)
-                                  output
-                                  #:log (%make-void-port "w"))
-                #t))))))))
+     (swh-download-directory (revision-directory revision) output
+                             #:log-port log-port))
     (#f
      #f)))
diff --git a/guix/ui.scm b/guix/ui.scm
index 7fbd4c63a2..e2cf2f1f5e 100644
--- a/guix/ui.scm
+++ b/guix/ui.scm
@@ -376,12 +376,14 @@ ARGS is the list of arguments received by the 'throw' handler."
     (('system-error . rest)
      (let ((err (system-error-errno args)))
        (report-error (G_ "failed to load '~a': ~a~%") file (strerror err))))
-    (('read-error "scm_i_lreadparen" message _ ...)
+    (('read-error _ message args ...)
      ;; Guile's missing-paren messages are obscure so we make them more
      ;; intelligible here.
-     (if (string-suffix? "end of file" message)
-         (let ((location (string-drop-right message
-                                            (string-length "end of file"))))
+     (if (or (string-suffix? "end of file" message) ;Guile < 3.0.6
+             (and (string-contains message "unexpected end of input")
+                  (member '(#\)) args)))
+         (let ((location (string-take message
+                                      (+ 2 (string-contains message ": ")))))
            (format (current-error-port) (G_ "~amissing closing parenthesis~%")
                    location))
          (apply throw args)))
@@ -490,12 +492,11 @@ part."
     (lambda _
       (setlocale LC_ALL ""))
     (lambda args
-      (display-hint (G_ "Consider installing the @code{glibc-utf8-locales} or
-@code{glibc-locales} package and defining @code{GUIX_LOCPATH}, along these
-lines:
+      (display-hint (G_ "Consider installing the @code{glibc-locales} package
+and defining @code{GUIX_LOCPATH}, along these lines:
 
 @example
-guix install glibc-utf8-locales
+guix install glibc-locales
 export GUIX_LOCPATH=\"$HOME/.guix-profile/lib/locale\"
 @end example