[rkangel]

> My intuition is that npm, cargo, zig build etc are all “wrong”. And that Bazel/Buck are architecturally correct.

Arguably yes. The fundamental issue is that Bazel etc. are "hermetic" build systems - every build step they run is in a sandbox with only the inputs (source files and tools) that you have explicitly specified - nothing implicit everything explicit. And relies on the output you get from those inputs being the same every time.

This gives a wonderful property of knowing exactly which steps need performing and being able to cache everything - your whole build DAG is a merkle tree.

The downside is that many build steps do not fit into that mould - they make arbitrary network calls, or want to be able to access corners of your filesystem, or produce slightly different outputs each time due to multithreading etc. So you need to work around this in some way to make the larger system work.

(FYI, this is exactly the same as the Nix and Guix build systems except that for them the granularity of a step is "build one package" rather than "build one C file")