$ git clone -n https://src.fedoraproject.org/rpms/libbase.git /var/lib/mock/f39-build-1489987-34502/root/chroot_tmpdir/scmroot/libbase
Cloning into '/var/lib/mock/f39-build-1489987-34502/root/chroot_tmpdir/scmroot/libbase'...
$ git fetch origin 9cd4b05f01423b4d3cab0f313bf523dde1935281:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libbase
 * [new ref]         9cd4b05f01423b4d3cab0f313bf523dde1935281 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9cd4b05 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild