packages.txt:build/common_virtualenv_packages.txt
# glean-sdk may not be installable if a wheel isn't available
# and it has to be built from source.
pypi-optional:glean-sdk==40.0.0:telemetry will not be collected
# Mach gracefully handles the case where `psutil` is unavailable.
pypi-optional:psutil==5.8.0:telemetry will be missing some data
pypi:zstandard==0.15.2