Can `cargo::rustc-env=VAR=VALUE` replace `export xx`

help
1

I'm using torch-sys crate, which needs absolute path to C library:

export LD_LIBRARY_PATH="$(pwd)/libtorch/lib:$LD_LIBRARY_PATH" \
    LIBTORCH="$(pwd)/libtorch" && \
    cargo run -p score --release

However, to release others from handling env vars, I tried cargo::rustc-env=VAR=VALUE instead:

And I ensure getting the right path by checking target/release/build/xx/output.

However, the latter does not compile, and the failing reason is same as if env vars are not set.

Maybe cargo::rustc-env=VAR=VALUE is just for things like producing git commit hash? Or is there any feasible way to achieve export's function in build.rs?

Maybe creating .cargo/config.toml and adding [env] by build.rs can work... But it may not be so graceful for modifying things out of OUT_DIR.

I'l got some sleep, sorry for my late replying.

2

Setting environment variants with buildrs sets it only for build time only for your crate. If it needs needs to be set at any other point (e.g. $LD_LIBRARY_PATH is read as part of program startup by the dynamic library loader) then you need to use a different mechanism.

3

You suddenly woke me up!

No matter how I set env vars to simplify development preparation, the user still need to export the dynamic lib path themselves. So it is not me who need to do so!