build: Set XDG_CACHE_HOME to avoid loading stale .go files.

Fixes <http://bugs.gnu.org/24120>.
Reported by myglc2 <myglc2@gmail.com>.

* Makefile.am (make-go): Set XDG_CACHE_HOME.

diff --git a/Makefile.am b/Makefile.am
index 543b101..8bae85e 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -389,11 +389,13 @@ CLEANFILES =                                      \
 # there that are newer than the local .scm files (for instance because the
 # user ran 'make install' recently).  When that happens, we end up loading
 # those previously-installed .go files, which may be stale, thereby breaking
-# the whole thing.
+# the whole thing.  Likewise, set 'XDG_CACHE_HOME' to avoid loading possibly
+# stale files from ~/.cache/guile/ccache.
 %.go: make-go ; @:
 make-go: $(MODULES) guix/config.scm guix/tests.scm
        $(AM_V_at)echo "Compiling Scheme modules..." ;                  \
        unset GUILE_LOAD_COMPILED_PATH ;                                \
+       XDG_CACHE_HOME=/nowhere                                         \
        host=$(host) srcdir="$(top_srcdir)"                             \
        $(top_builddir)/pre-inst-env                                    \
        $(GUILE) -L "$(top_builddir)" -L "$(top_srcdir)"                \