$ git clone -n https://src.fedoraproject.org/rpms/libgcroots.git /var/lib/mock/f40-build-784556-133440/root/chroot_tmpdir/scmroot/libgcroots
Cloning into '/var/lib/mock/f40-build-784556-133440/root/chroot_tmpdir/scmroot/libgcroots'...
$ git fetch origin c146fa85daff1376cc16f621827ace61f1e0fde0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libgcroots
 * [new ref]         c146fa85daff1376cc16f621827ace61f1e0fde0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c146fa8 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild