guix pull compiles every .scm file under a channel's checkout as an
ordinary package module and then loads each by its path-derived module
name to build the package cache. channels.scm and channels.d/*.scm never
had define-module clauses -- they relied on guix pull -C's implicit (guix
channels) import, which only applies to the -C argument itself, not to
files swept up as part of the channel's own module tree. That produced
first an unbound-variable error on `channel` at compile time, and after
adding plain use-modules imports, a "no code for module" error at
package-cache load time. Match the dual-purpose pattern already used by
metznet/machines/*.scm: a real define-module (so the module system finds
it under its expected name) plus a use-module for (guix channels) (so
guix pull -C channels.scm still works when it loads these directly).
noah metz
ff382c6056