$ git clone -n https://src.fedoraproject.org/rpms/perl-OpenGL.git /var/lib/mock/f41-build-815992-149916/root/chroot_tmpdir/scmroot/perl-OpenGL
Cloning into '/var/lib/mock/f41-build-815992-149916/root/chroot_tmpdir/scmroot/perl-OpenGL'...
$ git fetch origin b6b788c1e6e568962d7eeb5996c4c42ad4974c1a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-OpenGL
 * [new ref]         b6b788c1e6e568962d7eeb5996c4c42ad4974c1a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b6b788c Perl 5.40 rebuild