$ git clone -n https://src.fedoraproject.org/rpms/jackson-core.git /var/lib/mock/f40-build-2295347-56324/root/chroot_tmpdir/scmroot/jackson-core
Cloning into '/var/lib/mock/f40-build-2295347-56324/root/chroot_tmpdir/scmroot/jackson-core'...
$ git fetch origin 0784e40a5e70d1117790251b88dbbd42c42bd00d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jackson-core
 * [new ref]         0784e40a5e70d1117790251b88dbbd42c42bd00d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0784e40 [packit] 2.16.1 upstream release