$ git clone -n https://src.fedoraproject.org/rpms/perl-Syntax-Keyword-Defer.git /var/lib/mock/f41-build-816508-150225/root/chroot_tmpdir/scmroot/perl-Syntax-Keyword-Defer
Cloning into '/var/lib/mock/f41-build-816508-150225/root/chroot_tmpdir/scmroot/perl-Syntax-Keyword-Defer'...
$ git fetch origin cd5a269a03e772e6ef646b47d05ff92cbcdc62d2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Syntax-Keyword-Defer
 * [new ref]         cd5a269a03e772e6ef646b47d05ff92cbcdc62d2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cd5a269 Perl 5.40 rebuild