Fall back to eager registry when needed

[DilumAluthge]

No description provided.

[DilumAluthge]

@MilesCranmer If it fails with eager, after we set the environment variable to conservative, we need to make sure that juliacall does another Pkg.Registry.update(), otherwise the conservative value won't have any effect.

Does juliacall automatically run Pkg.Registry.update(), or do we need to do so manually ourselves in this package?

[DilumAluthge]

Does juliacall automatically run Pkg.Registry.update()

I'm guessing that the answer to this question is yes, based on this line (line 334):

https://github.com/JuliaPy/pyjuliapkg/blob/3a2c66019f098c1ebf84f933a46e7ca70e82792b/src/juliapkg/deps.py#L334-L334

But I'm not very familiar with pyjuliapkg.

[DilumAluthge]

I realize that we need to do this in every location where a Pkg operation might be needed.

[DilumAluthge]

So I'll have to refactor this functionality out, to make it easier to call in multiple locations.

[coveralls]

Pull Request Test Coverage Report for Build 12200236348

Details

• 31 of 31 (100.0%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.1%) to 93.52%

---

Totals
Change from base Build 12156732879:	0.1%
Covered Lines:	1371
Relevant Lines:	1466

---

💛 - Coveralls

[DilumAluthge]

@MilesCranmer I think this is ready for review now.

[DilumAluthge]

@MilesCranmer Can you enable CI on the new commit?

[MilesCranmer]

I made a few changes. Importantly I changed it so that it doesn't change the registry preference by default. Only if it fails to resolve do I switch things to eager.

What do you think of the edits?

[MilesCranmer]

Also, added some unittests

[MilesCranmer]

Thanks @DilumAluthge!