Q: Parallel installation of the same packages, or not?

[HenrikBengtsson]

Assume I have 10 packages, pkg1, pkg2, ..., pkg10, part of my reverse dependency check. They all depend on a dpkg package, which is not installed, and is not in the crancache cache.

How will dpkg be installed when I launch revdepcheck::revdep_check() in parallel with 20 workers? Will it end up:

1. installing dpkg once and only once, or

2. will each parallel check task attempt to install dpkg independently?

Knowing how it works helps to decided whether it's beneficial to pre-install/pre-populate the crancache cache, before launching the revdep checks. Especially so when there are many revdep packages with common dependencies.