cargo-zigbuild ignores the CARGO environment variable

[dmitrii-ubskii]

If cargo is not present in PATH, zigbuild (when run directly) fails with "Failed to run cargo build: No such file or directory (os error 2)", even if CARGO [1] is set correctly. This appears to be a bug in cargo-options [2], but since that is a tiny package, I'm also reporting it here. Cf. messense/cargo-options#8

[1] https://doc.rust-lang.org/cargo/reference/environment-variables.html
[2] https://github.com/messense/cargo-options/blob/main/src/common.rs#L167

[messense]

See cross-rs/cross#864 (comment)

[dmitrii-ubskii]

See cross-rs/cross#864 (comment)

Can't reproduce:

$ cargo run                                                                       
   Compiling env-test v0.1.0 (/Users/dmitriiubskii/workspace/misc/env-test)
    Finished dev [unoptimized + debuginfo] target(s) in 0.44s
     Running `target/debug/env-test`
env::var_os("CARGO")=Some("/Users/dmitriiubskii/.rustup/toolchains/stable-aarch64-apple-darwin/bin/cargo")
env::var("CARGO")=Ok("/Users/dmitriiubskii/.rustup/toolchains/stable-aarch64-apple-darwin/bin/cargo")

$ CARGO=~/Downloads/cargo cargo run                                               
   Compiling env-test v0.1.0 (/Users/dmitriiubskii/workspace/misc/env-test)
    Finished dev [unoptimized + debuginfo] target(s) in 0.50s
     Running `target/debug/env-test`
env::var_os("CARGO")=Some("/Users/dmitriiubskii/Downloads/cargo")
env::var("CARGO")=Ok("/Users/dmitriiubskii/Downloads/cargo")

$ CARGO=cargo cargo run 
    Finished dev [unoptimized + debuginfo] target(s) in 0.00s
     Running `target/debug/env-test`
env::var_os("CARGO")=Some("/Users/dmitriiubskii/workspace/misc/env-test/cargo")
env::var("CARGO")=Ok("/Users/dmitriiubskii/workspace/misc/env-test/cargo")

Granted, running CARGO=cross cargo run does print my ~/.rustup/... cargo path, but that's because cross isn't a valid path. The CARGO=cargo example uses the cargo file in the pwd.

[messense]

Fixed in messense/cargo-options@e620e56.