> One big downside is losing the ability to build any commit from source without meta-complexity creeping in. For example, let’s say that you are trying to do g

> One big downside is losing the ability to build any commit from source without meta-complexity creeping in. For example, let’s say that you are trying to do git bisect. At some point, git checks out an older commit, but the script fails to build from source because the binary that is being used to build the compiler is now the wrong version. Sure, this can be addressed, but this introduces unwanted complexity that contributors would rather not deal with. If it's the main concern of using a prior build of the compiler, an alternative solution is to develop a tool for contributors to automate and ease the process. For example, Rust has this: https://github.com/rust-lang/cargo-bisect-rustc https://github.com/rust-lang/cargo-bisect-rustc