$ git clone -n https://src.fedoraproject.org/rpms/kernel-headers.git /var/lib/mock/f39-build-730300-102657/root/chroot_tmpdir/scmroot/kernel-headers
Cloning into '/var/lib/mock/f39-build-730300-102657/root/chroot_tmpdir/scmroot/kernel-headers'...
$ git fetch origin 1efd41abe9af284b2e0522ab0b663b493fd87fa1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kernel-headers
 * [new ref]         1efd41abe9af284b2e0522ab0b663b493fd87fa1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1efd41a Fix tarball versioning for non rawhide