$ git clone -n https://src.fedoraproject.org/rpms/swift-lang.git /var/lib/mock/f41-build-852481-166358/root/chroot_tmpdir/scmroot/swift-lang
Cloning into '/var/lib/mock/f41-build-852481-166358/root/chroot_tmpdir/scmroot/swift-lang'...
$ git fetch origin ea96108046f8a1021f3bbd46d95c8cef7799626e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/swift-lang
 * [new ref]         ea96108046f8a1021f3bbd46d95c8cef7799626e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ea96108 Updated to Swift 6.0-RELEASE