Enable "verbose output" for build.rs

1

Hi - I'm working on a project that uses a build.rs. I'd like some way to enable verbose output for it. (In my case, I want to pass the verbose flag onto cmake.)

I was hoping to piggy-back off of rust's term.verbose configuration value, but I can't see a way to access that value from inside build.rs:

  • it's not listed in Environment variables Cargo sets for crates

  • when I inspect std::env::vars() from inside build.rs, CARGO_TERM_VERBOSE is not set, even if I have

    [term]
verbose = true

    ...inside my .cargo/config.toml

In general, how do people provide configurable behavior for build.rs? Do people just use env vars, or is there something more rust / cargo specific?

2

You can always output verbose output from your build.rs script, because Cargo will capture it and not print anything during normal successful builds. You can then use cargo build -vvv to print the whole output.

If you need it to be conditional, then I don't think there's anything in Cargo right now. You can always check for your own env variable.

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