Multiprocessing with n_jobs given by multiprocessing.cpu_count() is not optimal for
systems where not all CPU can be used (in particular, Docker, CI etc).

As suggested in the multiprocessing docs
(http://docs.python.org/3/library/multiprocessing.html#multiprocessing.cpu_count)
using len(os.sched_getaffinity(0)) might be better.

even if the machine have mores cores available

Patch taken from YBD: https://gitlab.com/baserock/ybd/blob/master/ybd/app.py#L227

buildstream/_project.py: Restrict max-jobs

See merge request !620

Pin ruamel.yaml version to <= 0.15

See merge request !630

This fixes #191

A note has been added to NEWS explaining backwards
compatibility issues

Patch for issue #191 support relative workspaces

Closes #191

See merge request !504

Valentin David authored Jul 25, 2018 and Valentin David committed Aug 10, 2018

Fixes #498

Set environment in bwrap command line instead of its environment

Closes #498

See merge request !565

This allows for users to configure fatal-warnings to be either a list of
warnings or simply True to consider all warnings as errors.

This commit deprecates the use of fail-on-overlap within project.conf,
this will now use the fatal-warnings configuration item.

tests: This modifys the tests/frontend/overlaps.py tests to support the
new fatal-warnings configuration. Backwards compatibility is also
tested for `fail-on-overlap`

_versions.py: BST_FORMAT_VERSION bumped to 12 for fatal-warnings

Fixes: #526

This follows the implementation of configurable warnings.

This includes detailing the use of `fatal-warnings` within project.conf

This also adds a deprecation notice to the fail on overlaps section.

This adds multiple tests for custom plugin warnings and core warnings,
providing checks for both cases which should cause warnings and errors
when configured as fatal.