metaconfig unit change for #15972.

p4raw-id: //depot/metaconfig@15973

diff --git a/U/perl/Extensions.U b/U/perl/Extensions.U
index e5bccc6..2739ca2 100644 (file)
--- a/U/perl/Extensions.U
+++ b/U/perl/Extensions.U
@@ -191,12 +191,18 @@ for xxx in $known_extensions ; do
                esac
                ;;
        threads|threads/shared)
-                case "$usethreads" in
-                true|$define|y)
-                        case "$useithreads" in
-                        $define|true|[yY]*) avail_ext="$avail_ext $xxx" ;;
-                        esac
-               esac
+               # threads and threads::shared are special cases.
+               # To stop people from asking "Perl 5.8.0 was supposed
+               # to have this new fancy threads implementation but my
+               # perl doesn't have it" and from people trying to
+               # (re)install the threads module using CPAN.pm and
+               # CPAN.pm then offering to reinstall Perl 5.8.0,
+               # the threads.pm and threads/shared.pm will always be
+               # there, croaking informatively ("you need to rebuild
+               # all of Perl with threads, sorry") when threads haven't
+               # been compiled in.
+               # --jhi
+               avail_ext="$avail_ext $xxx"
                ;;
        IPC/SysV|ipc/sysv)
                : XXX Do we need a useipcsysv variable here