Analyse following RPM build log snippet. Describe contents accurately, without speculation or suggestions for resolution.            
Your analysis must be as concise as possible, while keeping relevant information intact.
Snippet: 
+ /usr/bin/python3 -Bs /usr/lib/rpm/redhat/pyproject_buildrequires.py --generate-extras --python3_pkgversion 3 --wheeldir /builddir/build/BUILD/python-music21-9.5.0-build/music21-9.5.0/pyproject-wheeldir --output /builddir/build/BUILD/python-music21-9.5.0-build/python-music21-9.5.0-1.fc43.x86_64-pyproject-buildrequires -t
This snipped describes an invocation to generate build requirements for the package from the built wheel metadata. It contains a flag "-t" which adds the tox configuration to the build.