westonpace commented on pull request #12457: URL: https://github.com/apache/arrow/pull/12457#issuecomment-1043485424
@kou @pitrou We could use input on this approach. The Substrait integration is a little unique because the `.proto` files themselves are not owned by us. We could fork a copy of the proto files but that would make keeping up with updated versions a bit tricky. Protobuf is also a bit tricky because the version of the code generation tool (protoc) must match the version of the linked protobuf library exactly (this is different from flatbuffers which doesn't require a runtime dependency). Previously we were downloading the proto files using git and running protoc within the engine directory. This had some negative side effects (https://github.com/apache/arrow/pull/12454) mainly due to our use of git. Even beyond git however it was rather strange that this was resulting in a call to `externalproject_add` outside of `ThirdPartyToolchain.cmake` so @jvanstraten and I agreed it might be clear to treat Substrait as a "build-from-source only" third party dependency. This PR is @jvanstraten 's attempt to make that work but it is also odd as it requires a call to `add_arrow_lib` inside of `ThirdPartyToolchain.cmake`. Any suggestions on a better approach or feedback on our current approach would be very much welcomed. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
