$ git clone -n https://src.fedoraproject.org/rpms/perl-Mouse.git /var/lib/mock/f41-build-816895-150476/root/chroot_tmpdir/scmroot/perl-Mouse
Cloning into '/var/lib/mock/f41-build-816895-150476/root/chroot_tmpdir/scmroot/perl-Mouse'...
$ git fetch origin 023ac5f99a30a44d73b3ea59039488b7418af82c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Mouse
 * [new ref]         023ac5f99a30a44d73b3ea59039488b7418af82c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 023ac5f Perl 5.40 re-rebuild of bootstrapped packages