Notes for packagers of Python3
==============================

0. Faster build turnaround
--------------------------

By default, python builds with profile-guided optimization. This needs
an additional run of the test suite and it is generally slow.
PGO build takes around 50 minutes.

For development, use "--without profileopt" option to disable PGO. This
shortens the build time to ~5 minutes including test suite.

1. missing-stdlib-config.json.in
--------------------------------

Several stdlib modules are split into subpackages. So that users get a useful
hint when such a module is missing, we pass --with-missing-stdlib-config to
configure. The JSON file maps module names to the full error message that the
traceback module prints for a ModuleNotFoundError of that module.

Only names in sys.stdlib_module_names are eligible, so the test-only modules
from the testsuite subpackage cannot be given a custom message.
