$ git clone -n https://src.fedoraproject.org/rpms/ghc-servant-options.git /var/lib/mock/f39-build-1711994-41228/root/chroot_tmpdir/scmroot/ghc-servant-options
Cloning into '/var/lib/mock/f39-build-1711994-41228/root/chroot_tmpdir/scmroot/ghc-servant-options'...
$ git fetch origin b8b21b5dc5c9ae079d3e3cf2e20438a2511ad73f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-servant-options
 * [new ref]         b8b21b5dc5c9ae079d3e3cf2e20438a2511ad73f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b8b21b5 bump release