modules: Raise an error when a dependency could not be found....* guix/modules.scm (&missing-dependency-error): New error condition.
(source-module-dependencies): Raise it when 'search-path' returns #f.
* tests/modules.scm ("&missing-dependency-error"): New test.
Ludovic Courtès
2016-09-05
Add (guix modules)....* guix/modules.scm, tests/modules.scm: New files.
* Makefile.am (MODULES, SCM_TESTS): Add them.
* doc/guix.texi (G-Expressions): Add an example of
'source-module-closure'.