$ git clone -n https://src.fedoraproject.org/rpms/jstest-gtk.git /var/lib/mock/f42-build-3273909-41313/root/chroot_tmpdir/scmroot/jstest-gtk
Cloning into '/var/lib/mock/f42-build-3273909-41313/root/chroot_tmpdir/scmroot/jstest-gtk'...
$ git fetch origin b5cfc5a82af48cad8f96c8ee155a99a28cd551b6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jstest-gtk
 * [new ref]         b5cfc5a82af48cad8f96c8ee155a99a28cd551b6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b5cfc5a Rebuilt for https://fedoraproject.org/wiki/Fedora_42_Mass_Rebuild