$ git clone -n https://src.fedoraproject.org/rpms/mercurial.git /var/lib/mock/f40-build-2393582-60531/root/chroot_tmpdir/scmroot/mercurial
Cloning into '/var/lib/mock/f40-build-2393582-60531/root/chroot_tmpdir/scmroot/mercurial'...
$ git fetch origin 285db084e3a3e2cb8ab0806edfbf1186c22d52d3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mercurial
 * [new ref]         285db084e3a3e2cb8ab0806edfbf1186c22d52d3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 285db08 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild