build: "make check" now fails in a friendlier manner for missing Perl

* doc/Makefile.am (sc-lower-case-var): Don't redirect stderr of
$(PERL) (which is sometimes build-aux/missing) to /dev/null,
so that a failing "make check" explains that Perl is not installed.
Reported by James Youngman.

diff --git a/doc/Makefile.am b/doc/Makefile.am
index 57063df..be610a2 100644 (file)
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -115,7 +115,7 @@ find_upper_case_var =               \
      }                         \
    END {$$m and (warn "$(ME): do not use upper case in \@var{...}\n"), exit 1}'
 sc-lower-case-var:
-       $(AM_V_GEN)$(PERL) -e 1 2> /dev/null \
+       $(AM_V_GEN)$(PERL) -e 1 \
          && $(PERL) -lne $(find_upper_case_var) $(srcdir)/*.texi
 
 check: check-texinfo