bug#74453: running make failed when perl is installed in the very long path

[Karl Berry]

    >    ./configure PERL='/usr/bin/env perl'
    >
    > and it will substitute that into the scripts for you, but the configure
    > script in Automake 1.17 exits with a fatal error if it determines that
    > $PERL contains spaces.  We should probably make this non fatal since the
    > check is clearly too broad.

I changed this to a warning. Thanks. -k

-----------------------------------------------------------------------------
configure: make perl path with whitespace a warning, not error.

For https://bugs.gnu.org/74453.
See also https://bugs.gnu.org/62896.

* configure.ac (PERL): use AC_MSG_WARN.
diff --git a/configure.ac b/configure.ac
index e4c7a126c..fb2b37076 100644
--- a/configure.ac
+++ b/configure.ac
@@ -73,9 +73,11 @@ case $PERL in
    AC_MSG_ERROR([perl not found])
    ;;
  *' '* | *'    '*)
-  AC_MSG_ERROR([The path to your Perl contains spaces or tabs.
-This would cause build failures later or unusable programs.
-Please use a path without spaces and try again.])
+  AC_MSG_WARN([The path to your Perl contains spaces or tabs.
+This will likely cause build failures later or unusable programs.
+Unless you're specifying a full string for a #! line,
+as in "/usr/bin/env perl",
+please use a path without spaces and try again.])
   ;;
 esac