$ git clone -n https://src.fedoraproject.org/rpms/ghc-crypton-x509-system.git /var/lib/mock/f41-build-840168-160595/root/chroot_tmpdir/scmroot/ghc-crypton-x509-system
Cloning into '/var/lib/mock/f41-build-840168-160595/root/chroot_tmpdir/scmroot/ghc-crypton-x509-system'...
$ git fetch origin 2dcaecd57650d4c3f55171c7430d1ee53113ae10:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-crypton-x509-system
 * [new ref]         2dcaecd57650d4c3f55171c7430d1ee53113ae10 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2dcaecd import rhbz#2300470