$ git clone -n https://src.fedoraproject.org/rpms/R-pkgcache.git /var/lib/mock/f40-build-2268427-54740/root/chroot_tmpdir/scmroot/R-pkgcache
Cloning into '/var/lib/mock/f40-build-2268427-54740/root/chroot_tmpdir/scmroot/R-pkgcache'...
$ git fetch origin 40142034dd0a60675ba0224c4ba8ffe28e0a758b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-pkgcache
 * [new ref]         40142034dd0a60675ba0224c4ba8ffe28e0a758b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4014203 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild