$ git clone -n https://src.fedoraproject.org/rpms/ghc-json.git /var/lib/mock/f38-build-side-42-init-devel-623801-26363/root/chroot_tmpdir/scmroot/ghc-json
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-623801-26363/root/chroot_tmpdir/scmroot/ghc-json'...
$ git fetch origin 9ac3538d9fc2e6c57e76f6c4a5db06dcde3867e4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-json
 * [new ref]         9ac3538d9fc2e6c57e76f6c4a5db06dcde3867e4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9ac3538 Convert to %autorelease and %autochangelog