build-system/gnu: Report invocation errors in a human-friendly way.

* guix/build/utils.scm (report-invoke-error): New procedure.
* guix/build/gnu-build-system.scm (gnu-build): Guard against
'invoke-error?'.

1 files changed, 23 insertions, 20 deletions

diff --git a/guix/build/gnu-build-system.scm b/guix/build/gnu-build-system.scm
index 7d92b8d72e..3f68ad52ed 100644
--- a/guix/build/gnu-build-system.scm
+++ b/guix/build/gnu-build-system.scm
@@ -790,28 +790,31 @@ in order.  Return #t if all the PHASES succeeded, #f otherwise."
   ;; Encoding/decoding errors shouldn't be silent.
   (fluid-set! %default-port-conversion-strategy 'error)
 
-  ;; The trick is to #:allow-other-keys everywhere, so that each procedure in
-  ;; PHASES can pick the keyword arguments it's interested in.
-  (every (match-lambda
-           ((name . proc)
-            (let ((start (current-time time-monotonic)))
-              (format #t "starting phase `~a'~%" name)
-              (let ((result (apply proc args))
-                    (end    (current-time time-monotonic)))
-                (format #t "phase `~a' ~:[failed~;succeeded~] after ~,1f seconds~%"
-                        name result
-                        (elapsed-time end start))
-
-                ;; Issue a warning unless the result is #t.
-                (unless (eqv? result #t)
-                  (format (current-error-port) "\
+  (guard (c ((invoke-error? c)
+             (report-invoke-error c)
+             (exit 1)))
+    ;; The trick is to #:allow-other-keys everywhere, so that each procedure in
+    ;; PHASES can pick the keyword arguments it's interested in.
+    (every (match-lambda
+             ((name . proc)
+              (let ((start (current-time time-monotonic)))
+                (format #t "starting phase `~a'~%" name)
+                (let ((result (apply proc args))
+                      (end    (current-time time-monotonic)))
+                  (format #t "phase `~a' ~:[failed~;succeeded~] after ~,1f seconds~%"
+                          name result
+                          (elapsed-time end start))
+
+                  ;; Issue a warning unless the result is #t.
+                  (unless (eqv? result #t)
+                    (format (current-error-port) "\
 ## WARNING: phase `~a' returned `~s'.  Return values other than #t
 ## are deprecated.  Please migrate this package so that its phase
 ## procedures report errors by raising an exception, and otherwise
 ## always return #t.~%"
-                          name result))
+                            name result))
 
-                ;; Dump the environment variables as a shell script, for handy debugging.
-                (system "export > $NIX_BUILD_TOP/environment-variables")
-                result))))
-         phases))
+                  ;; Dump the environment variables as a shell script, for handy debugging.
+                  (system "export > $NIX_BUILD_TOP/environment-variables")
+                  result))))
+           phases)))