$ git clone -n https://src.fedoraproject.org/rpms/rubygem-sprockets.git /var/lib/mock/f39-build-1743478-41372/root/chroot_tmpdir/scmroot/rubygem-sprockets
Cloning into '/var/lib/mock/f39-build-1743478-41372/root/chroot_tmpdir/scmroot/rubygem-sprockets'...
$ git fetch origin 5219386b17f527e0e3549159928ae415968c22d9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-sprockets
 * [new ref]         5219386b17f527e0e3549159928ae415968c22d9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5219386 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild