02/02: build-self: Emit a useful message upon error.

[Ludovic Courtès]

civodul pushed a commit to branch master
in repository guix.

commit ac4d2ec81a9f7c439b21b4c4ae4a2e949c78ab2e
Author: Ludovic Courtès <address@hidden>
Date:   Thu Sep 13 10:23:39 2018 +0200

    build-self: Emit a useful message upon error.
    
    * build-aux/build-self.scm (build): Raise a '&message' condition instead
    of calling 'error'.
---
 build-aux/build-self.scm | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/build-aux/build-self.scm b/build-aux/build-self.scm
index 09979dc..306b2c6 100644
--- a/build-aux/build-self.scm
+++ b/build-aux/build-self.scm
@@ -25,6 +25,8 @@
   #:use-module (guix build-system gnu)
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-19)
+  #:use-module (srfi srfi-34)
+  #:use-module (srfi srfi-35)
   #:use-module (rnrs io ports)
   #:use-module (ice-9 match)
   #:use-module (ice-9 popen)
@@ -420,7 +422,15 @@ files."
            ;; Unsupported PULL-VERSION.
            (return #f))
           ((? string? str)
-           (error "invalid build result" (list build str))))))))
+           (raise (condition
+                   (&message
+                    (message (format #f "You found a bug: the program '~a'
+failed to compute the derivation for Guix (version: ~s; system: ~s;
+host version: ~s; pull-version: ~s).
+Please report it by email to <~a>.~%"
+                                     (derivation->output-path build)
+                                     version system %guix-version pull-version
+                                     %guix-bug-report-address)))))))))))
 
 ;; This file is loaded by 'guix pull'; return it the build procedure.
 build