* guix-build.in (derivations-from-package-expressions): Leave with an error message when SOURCE? is #t and P has no source. * tests/guix-build.sh: Add test.
* tests/guix-build.sh: New file. * Makefile.am (TESTS): Add it. (LOG_COMPILER): Rename to... (SCM_LOG_COMPILER): ... this. Move flags to... (AM_SCM_LOG_FLAGS): ... this. (TEST_EXTENSIONS, SH_LOG_COMPILER, AM_SH_LOG_FLAGS): New variables.