Additional tip for limiting number of CPUs

[azeey]

🦟 Bug fix

Summary

From https://robotics.stackexchange.com/a/97898/31574, colcon uses all available CPU cores when building a single package. Setting MAKEFLAGS="-j 1" would help if users are running out of memory.

Checklist

• [ ] Signed all commits for DCO
• [ ] Added tests
• [ ] Updated documentation (as needed)
• [ ] Updated migration guide (as needed)
• [ ] Consider updating Python bindings (if the library has them)
• [ ] codecheck passed (See contributing)
• [ ] All tests passed (See test coverage)
• [ ] While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[ahcorde]

https://github.com/Mergifyio backport humble iron