[wip] [squash] Add conda locks for CI

[bollwyvl]

References

• continuation of Maintenance: separate connection manager out of JupyterLabWidgetAdapter #45
• implements ideas from Continuous Integration Performance and Robustness Brainstorming #311, including dodo and conda-lock

Code changes

• adds conda-lock
  • checked in locks for all current CI excursions
  • lock.py is implemented as a dodo task generator
    • could be extended in the future to capture more of the workflow, from checkout to release
• using the locked env above (as show in the docs), ran the new black
  • had already encountered this over on [wip] Add completion configurer #328, so landing it here is as good as anywhere

Anecdata:

• absolute best case (cold cache on master, hot cache on the PR)

lint: linux py38

branch	conda cache	conda	env	yarn cache	yarn	total
master	0:00	3:08	1:54	0:00	1:05	9:33
pr	0:10	1:49	0:24	0:02	1:52	5:59
pr (run2)	0:06	1:31	0:25	0:01	1:58	5:46

test: win-64 py3.8

branch	conda cache	conda	env	yarn cache	yarn	total
master	0:00	7:38	0:00	0:00	3:36	50:17
pr TODO	0:00	0:52	5:52	0:04	0:00	?:??

• the yarn thing is troubling...

will update with a better windows benchmark set

User-facing changes

N/A

Backwards-incompatible changes

N/A

Chores

• linted
• tested
• documented
• changelog entry

[krassowski]

Btw before adding conda cache, conda was about 2:50, so it feels like download of packages was not a bottleneck. I even wondered if having local packages could result in slower times to solve the env., but then I was not using mamba yet (and the lock files were already on horizon).

[bollwyvl]

Ha, finally got a cache hit on windows for the conda packages. Now to see if it makes a lick of difference...

[bollwyvl]

Haven't dug into the repeated TabError fail (first on osx, then on win), but otherwise starting to look good.

I've also warmed back up the setup-miniconda PR which would directly support the lock files:

conda-incubator/setup-miniconda#74

[krassowski]

Stale?

[bollwyvl]

Definitely stale here, though the approach is sound. I'm working on some related stuff... Hopefully will have more to show soon.

[bollwyvl]

I'm not at my keyboard, but this can be safely closed!