tonsky

Maven's version resolution mechanism determines which version of a dependency to use when multiple versions are specified in a project's dependency tree. Here's how it works:

- Nearest Definition Wins: When multiple versions of the same dependency appear in the dependency tree, the version closest to your project in the tree will be used.

- First Declaration Wins: If two versions of the same dependency are at the same depth in the tree, the first one declared in the POM will be used.

> I’d love to lock my library to numpy 2.3.4, but if the developers of another library pin theirs to 2.3.5 then game over.

Why? Can’t you specify which version to use?

> would fail in languages like Python where dependencies are shared

And yet Java and Maven exist...

I updated the post, see near the bottom

Yeah but version ranges are fiction. Some says: we require libpupa 0.2.0+. Sure you can find a version in that range. But what if it doesn’t work? How can you know that your library will work with all the future libpupa releases in advance?

I worked for 20 years in an ecosystem that didn’t have lockfiles and had reproducible builds before the term was invented, and now you come and tell me that it couldn’t be?

> Lockfiles are essential for somewhat reproducible builds.

No they are not. Fully reproducible builds have existed without lockfiles for decades

One of the versions will be picked up. If that version doesn’t work, you can try another one. The process is exactly the same

It’s totally fine in Maven, no need to rebuild or repackage anything. You just override version of libinsecure in your pom.xml and it uses the version you told it to

Clojure Electric is different. It’s not really a sync, it’s more of a thin client. It relies of having fast connection to server at all times, and re-fetches everything all the time. They innovation is that they found a really, really ergonomic way to do it

If you think of an existing database, like Postgres, sure. It’s not very convenient.

What I am saying is, in a perfect world, database and server will be the one and run code _and_ data at the same time. There’s really no good reason why they are separated, and it causes a lot of inconveniences right now.

Ah, no. Not really. People sometimes think about conflict resolution as a problem that needs to be solved. But it’s not solvable, not really. It’s part of the domain, it’s not going anywhere, it’s irreducible complexity.

You _will_ have conflicts (because your app is distributed and there are concurrent writes). They will happen on semantic level, so only you (app developer) _will_ be able to solve them. Database (or any other magical tool) can’t do it for you.

Another misconception is that conflict resolution needs to be “solved” perfectly before any progress can be made. That is not true as well. You might have unhandled conflicts in your system and still have a working, useful, successful product. Conflicts might be rare, insignificant, or people (your users) will just correct for/work around them.

I am not saying “drop data on the floor”, of course, if you can help it. But try not to overthink it, either.

> There's no such thing as reliable network in the world

I’m not saying there is

- You can have many sync engines

- Sync engines might only solve small and medium scale, that would be a huge win even without large scale

It’s not as simple as you make it sound:

- Reliable communication is hard - Optimistic writes should on client are hard - Tracking subsets of data is hard (you don't want the entirety of Datomic on the client, do you?) - Permissions are hard in this model

Why didn't I implement it? Mostly comes down to free time. It's a hobby project and it's hard to find time for it. I also stopped writing web apps so immediate pressure for this went away.