$ git clone -n https://src.fedoraproject.org/rpms/libxcrypt.git /var/lib/mock/f40-build-2219999-52649/root/chroot_tmpdir/scmroot/libxcrypt
Cloning into '/var/lib/mock/f40-build-2219999-52649/root/chroot_tmpdir/scmroot/libxcrypt'...
$ git fetch origin 87291dc73c81f79439c0ba680da639d6483dc30b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libxcrypt
 * [new ref]         87291dc73c81f79439c0ba680da639d6483dc30b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 87291dc Fix C compatibility issue in the configure script