$ git clone -n https://src.fedoraproject.org/rpms/rubygem-tk.git /var/lib/mock/f42-build-865215-172845/root/chroot_tmpdir/scmroot/rubygem-tk
Cloning into '/var/lib/mock/f42-build-865215-172845/root/chroot_tmpdir/scmroot/rubygem-tk'...
$ git fetch origin 4436be150fa0788b3703049539a432a188cefea0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-tk
 * [new ref]         4436be150fa0788b3703049539a432a188cefea0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4436be1 Rebuild for https://fedoraproject.org/wiki/Changes/Ruby_3.4