Hello,
On our project (Apache Arrow - https://arrow.apache.org/) we're using CMake for the C++ source tree and have many external dependencies fetched using ExternalProject. In turn building those dependencies can make up a significant portion of build times on CI services, especially AppVeyor. So I've been looking for a solution to cache those third-party builds from one CI run to the other. Right now, what I'm trying to do is to set EP_BASE to a well-known base directory and ask AppVeyor to cache and restore that directory in each new build. The AppVeyor caching seems to work fine (the EP_BASE directory is saved and restored). However, it seems that nevertheless CMake will rebuild all those projects again, despite the cached build results. This is with CMake 3.12.1 on Windows. Here is the log for an example build step, here the zstd library: https://ci.appveyor.com/project/pitrou/arrow/build/1.0.700/job/i4tj6tifp4xq1mjn?fullLog=true#L803 As you can see, CMake notices the downloaded tarball is up-to-date and doesn't download it again, but it still extracts it again (why?) and builds the source code anew. Yet the entire EP_BASE directory (here "C:/Users/appveyor/arrow-externals") is cached and restored by AppVeyor. Did someone manage to make this work, and/or is there another solution? Thank you Regards Antoine. -- Powered by www.kitware.com Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Kitware offers various services to support the CMake community. For more information on each offering, please visit: CMake Support: http://cmake.org/cmake/help/support.html CMake Consulting: http://cmake.org/cmake/help/consulting.html CMake Training Courses: http://cmake.org/cmake/help/training.html Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Follow this link to subscribe/unsubscribe: https://cmake.org/mailman/listinfo/cmake
