$ git clone -n https://src.fedoraproject.org/rpms/rubygem-gio2.git /var/lib/mock/f42-build-865439-173130/root/chroot_tmpdir/scmroot/rubygem-gio2
Cloning into '/var/lib/mock/f42-build-865439-173130/root/chroot_tmpdir/scmroot/rubygem-gio2'...
$ git fetch origin 2b6e2c319e7a472aea43bc7c483445f7f857c8c7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-gio2
 * [new ref]         2b6e2c319e7a472aea43bc7c483445f7f857c8c7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2b6e2c3 Rebuild for https://fedoraproject.org/wiki/Changes/Ruby_3.4