An option for #1175:
$ git fetch origin pull/1287/head
$ git archive --output=libsecp256k1-PR1287.tar.gz FETCH_HEAD
$ sha256sum libsecp256k1-PR1287.tar.gz
6e6fd21afd935e572b138258f782fed60bb11fa88aa51a9866f10cca5d25c39c libsecp256k1-PR1287.tar.gz
$ git archive --output=libsecp256k1-PR1287.zip FETCH_HEAD
$ sha256sum libsecp256k1-PR1287.zip
e108fc4902502640eee2cf4bb69501a494904c4dcd0763c072cc4acaed565861 libsecp256k1-PR1287.zip