$ git clone -n https://src.fedoraproject.org/rpms/perl-File-CheckTree.git /var/lib/mock/f45-build-23463-597/root/chroot_tmpdir/scmroot/perl-File-CheckTree
Cloning into '/var/lib/mock/f45-build-23463-597/root/chroot_tmpdir/scmroot/perl-File-CheckTree'...
$ git fetch origin 3693c52168e8a7e10fc41576f14def5658725f86:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-File-CheckTree
 * [new ref]         3693c52168e8a7e10fc41576f14def5658725f86 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3693c52 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild