Makefile.PL: allow overriding "prove" from make CLI

Development versions of Perl install "prove$VERSION"
where $VERSION is something like "5.31.7".  This makes
it easier to test everything we have against development
versions of Perl5.

Note: I could not find a way to get quoting right to use the
"--exec $(PERL)" option of prove(1), but that would be the best
option for working transparently after running:

	perl5.31.7 Makefile.PL

diff --git a/Makefile.PL b/Makefile.PL
index 0daa6107483214e3169fbfe05f5f0cc1bb74d363..3020f25ac00807ac47c5fcddc2433742de8831f9 100644 (file)
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -146,6 +146,7 @@ WriteMakefile(
 
 sub MY::postamble {
   <<EOF;
+PROVE = prove
 # support using eatmydata to speed up tests (apt-get install eatmydata):
 # https://www.flamingspork.com/projects/libeatmydata/
 EATMYDATA =
@@ -168,7 +169,7 @@ check-manifest :: MANIFEST
        if git ls-files >\$?.gen 2>&1; then diff -u \$? \$?.gen; fi
 
 check:: pure_all check-manifest
-       \$(EATMYDATA) prove -bvw -j\$(N)
+       \$(EATMYDATA) \$(PROVE) -bvw -j\$(N)
 
 lib/PublicInbox/UserContent.pm :: contrib/css/216dark.css
        \$(PERL) -I lib \$@ \$?