replace boost::filesystem with std::filesystem. std::filesystem is part of C++17 but before gcc 9 it was implemented in a separate library that we had to link against. Since gcc 8 is quite old (Ubuntu 20.04 is using gcc 9.3), it's safe to make the chang.
wait for the input files to appear instead of throwing an error
This PR does two things:
boost::filesystem
withstd::filesystem
.std::filesystem
is part of C++17 but before gcc 9 it was implemented in a separate library that we had to link against. Since gcc 8 is quite old (Ubuntu 20.04 is using gcc 9.3), it's safe to make the chang.CI