$ git clone -n https://src.fedoraproject.org/rpms/rust-servo_arc0.2.git /var/lib/mock/f39-build-1961003-43268/root/chroot_tmpdir/scmroot/rust-servo_arc0.2
Cloning into '/var/lib/mock/f39-build-1961003-43268/root/chroot_tmpdir/scmroot/rust-servo_arc0.2'...
$ git fetch origin 97add5f9f0caa2d9be3e8c15c0196157c31164de:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-servo_arc0.2
 * [new ref]         97add5f9f0caa2d9be3e8c15c0196157c31164de -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 97add5f Initial import (servo_arc 0.2 compat package)