Errors in modules are suppressed?

[Daniel Schäfer]

Hi all,

I'm using modules to split up my system configuration in multiple files 
(not sure whether that's the right approach).
However, when a used module contains an error, `guix system` does not 
provide a helpful error message, it just says:

  $ sudo guix system build config.scm
  ice-9/eval.scm:223:20: In procedure proc:
  error: bar: unbound variable
  hint: Did you forget `(use-modules (foo))'?

when I try to use `bar` in my original file.

For a minimal working example, change your system's configuration file 
like this:

+(add-to-load-path ".")
-(use-modules (gnu))
+(use-modules (gnu)
+             (foo))
 (use-service-modules desktop networking ssh xorg)

 (operating-system
-  (locale "en_US.utf8")
+  (locale bar)


And add the new module foo.scm, which contains an error by design:

(define-module (foo)
 #:export (bar))

(this is not defined)
(define bar "en_US.utf8")


I'd be glad to hear about any tips to get the proper error message.

Thanks,
Daniel