From a09ec3a5af3eb38b31d4eff0f323a2c47b82c114 Mon Sep 17 00:00:00 2001 From: Ludovic Courtès Date: Mon, 10 Dec 2012 22:53:28 +0100 Subject: Have `%nixpkgs-directory' default to #f when $NIXPKGS is the empty string. * guix/utils.scm (%nixpkgs-directory): Set to #f when the `NIXPKGS' environment variable is set but empty. Reported by Andreas Enge . --- guix/utils.scm | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'guix/utils.scm') diff --git a/guix/utils.scm b/guix/utils.scm index 5ec8f3736d..453b3843dd 100644 --- a/guix/utils.scm +++ b/guix/utils.scm @@ -156,7 +156,15 @@ evaluate to a simple datum." (define %nixpkgs-directory (make-parameter ;; Capture the build-time value of $NIXPKGS. - (or %nixpkgs (getenv "NIXPKGS")))) + (or %nixpkgs + (and=> (getenv "NIXPKGS") + (lambda (val) + ;; Bail out when passed an empty string, otherwise + ;; `nix-instantiate' will sit there and attempt to read + ;; from its standard input. + (if (string=? val "") + #f + val)))))) (define* (nixpkgs-derivation attribute #:optional (system (%current-system))) "Return the derivation path of ATTRIBUTE in Nixpkgs." -- cgit v1.2.3