Some more research into the build issue on OSX. I've now learned the following. Originally cmake provided its own cmake library for Boost. The Boost project is developing its own cmake files and apparently brew switched the default from the cmake internal build to the boost provided build from version 1.70 to 1.71. It would seem that this is not entirely bug free yet, and a variable is provided to revert to the cmake internal stuff: "Boost_NO_BOOST_CMAKE". For prjtrellis to build it needs this flag set (on OSX at least). I've posted an update to the @twam repository (https://github.com/twam/homebrew-openfpga/issues/2). With this brew formula prjtrellis builds again on OSX without special interventions. I think the root cause is that brew does separate builds for boost and boost-python3 and as a result of that does not create the /usr/local/lib/cmake/boost_python3-1.71.0 entry. As a result of this, the Boost cmake system cannot find boost-python3 anymore.
CMake fix provided by pnrhub via https://github.com/twam/homebrew-openfpga/issues/2. Background from gitter:
Some more research into the build issue on OSX. I've now learned the following. Originally cmake provided its own cmake library for Boost. The Boost project is developing its own cmake files and apparently brew switched the default from the cmake internal build to the boost provided build from version 1.70 to 1.71. It would seem that this is not entirely bug free yet, and a variable is provided to revert to the cmake internal stuff: "Boost_NO_BOOST_CMAKE". For prjtrellis to build it needs this flag set (on OSX at least). I've posted an update to the @twam repository (https://github.com/twam/homebrew-openfpga/issues/2). With this brew formula prjtrellis builds again on OSX without special interventions. I think the root cause is that brew does separate builds for boost and boost-python3 and as a result of that does not create the /usr/local/lib/cmake/boost_python3-1.71.0 entry. As a result of this, the Boost cmake system cannot find boost-python3 anymore.