perl Git::LoadCPAN: emit better errors under NO_PERL_CPAN_FALLBACKS

diff --git a/Makefile b/Makefile
index 7b97699864e22d008abdc7c61ed6c25d5dc2aeac..4e0cdb3ca4a3c722c12b7219c72c978dddac45bd 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -296,6 +296,12 @@ all::
 #
 # Define NO_PERL if you do not want Perl scripts or libraries at all.
 #
+# Define NO_PERL_CPAN_FALLBACKS if you do not want to install bundled
+# copies of CPAN modules that serve as a fallback in case the modules
+# are not available on the system. This option is intended for
+# distributions that want to use their packaged versions of Perl
+# modules, instead of the fallbacks shipped with Git.
+#
 # Define PYTHON_PATH to the path of your Python binary (often /usr/bin/python
 # but /usr/bin/python2.7 on some platforms).
 #
@@ -2305,12 +2311,17 @@ LIB_CPAN_GEN := $(patsubst perl/%.pm,perl/build/lib/%.pm,$(LIB_CPAN))
 
 ifndef NO_PERL
 all:: $(LIB_PERL_GEN)
+ifndef NO_PERL_CPAN_FALLBACKS
 all:: $(LIB_CPAN_GEN)
 endif
+NO_PERL_CPAN_FALLBACKS_SQ = $(subst ','\'',$(NO_PERL_CPAN_FALLBACKS))
+endif
 
 perl/build/lib/%.pm: perl/%.pm
        $(QUIET_GEN)mkdir -p $(dir $@) && \
-       sed -e 's|@@LOCALEDIR@@|$(localedir_SQ)|g' < $< > $@
+       sed -e 's|@@LOCALEDIR@@|$(localedir_SQ)|g' \
+           -e 's|@@NO_PERL_CPAN_FALLBACKS@@|$(NO_PERL_CPAN_FALLBACKS_SQ)|g' \
+       < $< > $@
 
 perl/build/man/man3/Git.3pm: perl/Git.pm
        $(QUIET_GEN)mkdir -p $(dir $@) && \