$ git clone -n https://src.fedoraproject.org/rpms/perl-Regexp-Grammars.git /var/lib/mock/f45-build-26044-614/root/chroot_tmpdir/scmroot/perl-Regexp-Grammars
Cloning into '/var/lib/mock/f45-build-26044-614/root/chroot_tmpdir/scmroot/perl-Regexp-Grammars'...
$ git fetch origin 41bbd77f20a80be915b81f4943d23a9cf7cf5dc2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Regexp-Grammars
 * [new ref]         41bbd77f20a80be915b81f4943d23a9cf7cf5dc2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 41bbd77 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild