Missing build information in update_build_if function

[Forbinn]

Description of Problem, Request, or Question

The update_build_if function is missing information inside the build object. The README precise that you can use the os information (https://github.com/conan-io/conan-package-tools#filtering-or-modifying-the-configurations) but it does not seems to be present.

from cpt.packager import ConanMultiPackager

if __name__ == "__main__":
    builder = ConanMultiPackager()
    builder.add_common_builds(pure_c=False)
    builder.update_build_if(lambda build: print(build.settings))

• On linux -> {'arch': 'x86', 'build_type': 'Release', 'compiler': 'gcc', 'compiler.version': '5', 'compiler.libcxx': 'libstdc++11'}
• On Windows -> {'compiler': 'Visual Studio', 'compiler.version': '14', 'arch': 'x86', 'build_type': 'Release', 'compiler.runtime': 'MT'}

Environment Details

• Conan Package Tools Version: 0.35.1
• Conan version: conan 1.37.2
• Python version: python 3.7.9