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