Since sometime yesterday, all the gcc/clang develop runners I maintain (not sure about Visual Studio, that machine has been down for updates) have been failing, before the tests suite can even start running. Master still looks good. They end with the following: - bzip2 : yes [30] - lzma : yes [30] - zstd : no [30] - lzma : yes (cached) [30] - has_lzma_cputhreads builds : no [2] - auto_ptr : yes [3] error: Unable to find file or target named error: '/python//numpy' error: referred to from project at error: '../libs/python/build' I believe this is because of the python ( https://github.com/boostorg/python/pull/362) and build ( https://github.com/boostorg/build/pull/726) pull requests that were merged in around that time. The question is, why is this causing an issue....I have some vague memory of the regression test suite always using build from master? Am I remembering this correctly? If so, I think we may need to back out the python change until build's develop branch merges to master? I'm seeing this across multiple docker images, one that has been rather stable is this: https://hub.docker.com/layers/teeks99/boost-cpp-docker/clang-11/images/sha25... running with this user-config.jam: https://github.com/teeks99/boost-cpp-docker/blob/master/clang-11/user-config... and numpy installed for both python 2 and 3. Thoughts? Tom