Hi,

I'm working on a new build-systems from a channel.
When building a package using this build-system, I get

--8<---------------cut here---------------start------------->8---
building /gnu/store/j1qracwgv7qbxslbf6755z8wcwlv3bcf-foobar-qux-hires-2010.drv...
Backtrace:
           4 (primitive-load "/gnu/store/v4yp12m19g3bnn901kxa65xpifp?")
In ice-9/eval.scm:
   191:35  3 (_ #f)
   213:21  2 (_ #f)
   223:20  1 (proc #<directory (guile-user) 5cf140>)
In unknown file:
           0 (%resolve-variable (7 . foobar-build) #<directory (gui?>)

ERROR: In procedure %resolve-variable:
Unbound variable: foobar-build
builder for `/gnu/store/j1qracwgv7qbxslbf6755z8wcwlv3bcf-foobar-qux-hires-2010.drv' failed with exit code 1
build of /gnu/store/j1qracwgv7qbxslbf6755z8wcwlv3bcf-foobar-qux-hires-2010.drv failed
View build log at '/var/log/guix/drvs/j1/qracwgv7qbxslbf6755z8wcwlv3bcf-foobar-qux-hires-2010.drv.bz2'.
guix build: error: build of `/gnu/store/j1qracwgv7qbxslbf6755z8wcwlv3bcf-foobar-qux-hires-2010.drv' failed
--8<---------------cut here---------------end--------------->8---

Here is the offending part:

--8<---------------cut here---------------start------------->8---
(define* (foobar-build store name inputs
                        #:key
                        (tests? #f)
                        (build-targets #f)
                        (phases '(@ (my-guix build foobar-build-system)
                                    %standard-phases))
                        (outputs '("out"))
                        (search-paths '())
                        (system (%current-system))
                        (guile #f)
                        (substitutable? #t)
                        (imported-modules %foobar-build-system-modules)
                        (modules '((my-guix build foobar-build-system)
                                   (guix build utils))))
   ...
--8<---------------cut here---------------end--------------->8---

The default value of the key argument "modules" is the problem.  Is it
possible that the builder cannot find channel modules, or any module out
of the Guix tree?

-- 
Pierre Neidhardt
https://ambrevar.xyz/