build: use lerna run build instead of lerna exec

[georgexu99]

Using run build rather than exec allows us to leverage nx build caching

[MarshallOfSound]

Using run build rather than exec allows us to leverage nx build caching

It also makes the tsc compilation dramatically slower

[georgexu99]

I ran some benchmarks, and it looks like the downside of not running tsc within root context slows the command down by ~3-5 seconds for the initial run.

I think because we don't run this command locally very often (though the local amortized build time is faster for n > 1 runs vs .what we have currently), if we enable nx distributed caching , the benefit we get from CI breezing through the build step could be worth an extra couple seconds for the first yarn build?

[erickzhao]

from CI breezing through the build step

Do we have numbers of how this might happen? Is there a way to test this out without merging to main first?

[erikian]

from CI breezing through the build step

Isn't this a use case for CI caching (think https://github.com/actions/cache or https://docs.gitlab.com/ee/ci/caching/)? If incremental compilation is on and the built files are cached, future builds should be faster because only modified .ts files will be rebuilt.

[georgexu99]

close in favor of #3090

which uses incremental builds + top level tsc