The build system uses pools for mutual exclusion. Currently multiple
instances of these pools exist which defeats their purpose.
For example, it can cause concurrent instances of "pip install" which is
not safe.
Bug: 390
No-Docs-Update-Reason: bug fix
Change-Id: I114d2428d747a6d5a68a024a0177343ee82cad76
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/48520
Commit-Queue: Michael Spang <spang@google.com>
Reviewed-by: Wyatt Hepler <hepler@google.com>
