$ git clone -n https://src.fedoraproject.org/rpms/cpprest.git /var/lib/mock/f40-build-2074442-49392/root/chroot_tmpdir/scmroot/cpprest
Cloning into '/var/lib/mock/f40-build-2074442-49392/root/chroot_tmpdir/scmroot/cpprest'...
$ git fetch origin a12ceb3569273255e4e3aaeae1a4526823c2bf75:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/cpprest
 * [new ref]         a12ceb3569273255e4e3aaeae1a4526823c2bf75 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a12ceb3 New upstream version 2.10.19