I tried Basel, Buck2 and Pants for a greenfield mono repo recently, Rust and Python heavy.

Of the three, I went with Buck2. Maybe just circumstance with Rust support being good and not built to replace Cargo?

Bazel was a huge pain - broke all standard tooling by taking over Cargos job, then unable to actually build most packages without massive multi-day patching efforts.

Pants seemed premature - front page examples from the docs didn’t work, apparently due to breaking changes in minor versions, and the Rust support is very very early days.

Buck2 worked out of the box exactly as claimed, leaves Cargo intact so all the tooling works.. I’m hopeful.

Previously I’ve used Make for polyglot monorepos.. but it requires an enormous amount of discipline from the team, so I’m very keen for a replacement with less foot guns

Personally, I write my own build systems.

Any readily available build system is more of a meta-language onto which you code your own logic, but with limited control and capabilities. Might as well take control of the whole stack in a real programming language.

Building my own build system lets me optimize my workflow end-to-end, from modular version management, packaging and releasing, building and testing, tightly integrating whatever tool or reporting I want, all seamlessly under the same umbrella.

I mostly do C++, Assembly, eBPF, Python (including C++ Python modules), and multi-stage codegen on Linux, so I haven't really looked at the complexity of other languages or platforms.