consider using `env::var(CARGO)` instead of looking for cargo in PATH

[jyn514]

Description

Currently, cargo-clippy hard-codes cargo as the command to run and looks for it in PATH:

rust-clippy/src/main.rs

Line 108 in 1c8cbe7

let mut cmd = Command::new("cargo");

This means that, e.g., running /home/jyn/.cargo/bin/cargo-clippy directly, without having ~/.cargo in PATH, will not work.

I cannot think of a use case where this would break things, but it makes me a little uncomfortable. Cargo sets the environment variable CARGO for subcommands: https://doc.rust-lang.org/cargo/reference/environment-variables.html#environment-variables-cargo-sets-for-crates
It would be nice if clippy defaulted to that environment variable before falling back to the cargo in PATH.

Version

clippy 0.1.76 (ae25d69dea5 2023-11-17)

Additional Labels

No response

[Alexendoo]

Fixed by #11944