$ git clone -n https://src.fedoraproject.org/rpms/gtk4.git /var/lib/mock/f41-build-side-1-2641588-26721/root/chroot_tmpdir/scmroot/gtk4
Cloning into '/var/lib/mock/f41-build-side-1-2641588-26721/root/chroot_tmpdir/scmroot/gtk4'...
$ git fetch origin 7b0f655d23ad055b4b375025b150f9a17a22e310:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gtk4
 * [new ref]         7b0f655d23ad055b4b375025b150f9a17a22e310 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7b0f655 Update to 4.15.6