In which step does pants inject all the pythonpath before launching a test? the command line at this stage https://github.com/pantsbuild/pants/blob/9f2bd17640a29ee7ad34d353efdd979222a75f70/src/python/pants/backend/python/tasks/pytest_run.py#L552 ends up being

/Users/yic/workspace/pants_ij/build-support/pants_dev_deps.venv/bin/python2.7 /Users/yic/workspace/pants/.pants.d/python-setup/chroots/24101dfe6db56d32e0ad933ba47345abd2ea3fd4 —resultlog=... --confcutdir /Users/yic/workspace/pants --color yes examples/tests/python/example_test/hello/greet/greet.py

and

os.environ

contains only the chroot and not the wheels. but where does all the

chroot/.deps/…whl

get injected?