$ git clone -n https://src.fedoraproject.org/rpms/rubygem-unicode.git /var/lib/mock/f42-build-865218-172845/root/chroot_tmpdir/scmroot/rubygem-unicode
Cloning into '/var/lib/mock/f42-build-865218-172845/root/chroot_tmpdir/scmroot/rubygem-unicode'...
$ git fetch origin 79bf6fd0d63cab9204b469524ce787852f090e77:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-unicode
 * [new ref]         79bf6fd0d63cab9204b469524ce787852f090e77 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 79bf6fd Rebuild for https://fedoraproject.org/wiki/Changes/Ruby_3.4