Working on "Use std::filesystem. Remove Boost Filesystem & System" #20744, I found an unfortunate pitfall -- boost/process.hpp depends on boost::filesystem when cross-compiling for Windows. It happens in Guix environment as well.
The goal of this issue is to discuss and find a solution to get rid of boost::filesystem.
Is it a problem that something uses boost::filesystem? Does it conflicts with our own (non-use), or is it a lot of extra code to build? At least it could be specifically gated for the windows build.
In the longer run boost::process could be replaced with another library, or some own solution. It doesn't seem like rocket science though it is tricky to get right in a cross-platform way (especially windows, I guess :smile:)
Cross-compiling is successful only when a build system has been configured with --disable-external-signer.