$ git clone -n https://src.fedoraproject.org/rpms/ghc-data-accessor.git /var/lib/mock/f39-build-1511001-35514/root/chroot_tmpdir/scmroot/ghc-data-accessor
Cloning into '/var/lib/mock/f39-build-1511001-35514/root/chroot_tmpdir/scmroot/ghc-data-accessor'...
$ git fetch origin d4f058e24b4c47e16d2e91f58e1222d456d39a0b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-data-accessor
 * [new ref]         d4f058e24b4c47e16d2e91f58e1222d456d39a0b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d4f058e bump release