Hilariously, my pentadactyl shortcut for the oxidation plan was HG. I took that as a sign to read the article. Has hg ever considered a long-running "daemon-like" process instead? It could be instantiated automatically by the first call to hg and then it can die after it hasn't been used for a while. It would probably be racy and hard to support on multiple OS's though...

They do kind of have this: https://www.mercurial-scm.org/wiki/CommandServer

Though it looks like it's more about supplying a way to embed hq in a proprietary (or non-Python) application via subprocess communication rather than directly importing the GPL modules or having to string-parse responses. There doesn't seem to be provision for interacting with the server directly from the command line, which is odd, since this pattern is well established from Java land (bazel, for example).

The pkg_resources problem is specific for programs that use entry points (and it can be avoided), not a general CPython issue, and AFAICT is not related to Mercurial's plan to include Rust.

Interesting; I hadn't realised this, thanks for the clarification.

I'm aware of yapsy as a lightweight plugin system, but entry_points really is the gold standard in terms of Python extensibility. It's a shame it can't be made more performant.

Thanks for this, it makes for an interesting read, especially for someone who only dips his toe in python programming lightly once in a while.