Subject: [PATCH v2] channels: Print backtrace when generating package cache fails.

From: Josselin Poiret <[email-masked]>
Date: Sat, 11 Jun 2022 18:59:38 +0200

* guix/channels.scm (package-cache-file): Add a throw handler around
the generate-package-cache call, and print backtrace in it.
---
IRC promptly pointed out that Guix has required Guile ver>=2 since way before
guix repl and guix pull were ever a thing, thus drop the Guile 1 compatibility
code.  Enjoy this v2

Best,
Josselin
 guix/channels.scm | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/guix/channels.scm b/guix/channels.scm
index 20f347d34f..fde425327d 100644
--- a/guix/channels.scm
+++ b/guix/channels.scm
@@ -911,7 +911,14 @@ (define build
                 (format (current-error-port)
                         "Generating package cache for '~a'...~%"
                         #$profile)
-                (generate-package-cache #$output))
+                ;; This script runs through (primitive-load), which by default
+                ;; doesn't print backtraces when it encounters an exception,
+                ;; so manually do it.  Use with-throw-handler because it is
+                ;; supported by all Guile versions.
+                (with-throw-handler #t
+                  (lambda () (generate-package-cache #$output))
+                  (lambda (key . args)
+                      (backtrace))))
               (mkdir #$output))))
 
     (gexp->derivation-in-inferior "guix-package-cache" build
-- 
2.36.1