Expected behaviour of build.env.passthrough in 0.2.2?

[SanityOverflow]

I recently updated cross to 0.2.2, and noticed that env passthrough via build.env doesn't seem to work the same way as in 0.2.1.

For a minimal reproduction, if I have a Cross.toml file like so in any Rust project (e.g. just run cargo init):

[build.env]
passthrough = ["CARGO_TERM_COLOR"]

and run:

CARGO_TERM_COLOR=never cross build --target aarch64-unknown-linux-gnu

this will still give me a coloured output, as if the env var was not set or passed through. Note that in 0.2.1, this will give me an uncoloured output.

However, if in 0.2.2, I instead write:

[target.aarch64-unknown-linux-gnu.env]
passthrough = ["CARGO_TERM_COLOR"]

and run the same command as above, then it will work properly.

I'm not sure if this is expected behaviour or not, hence why I didn't reporting it as a bug/issue. Was the previous behaviour in 0.2.1 changed such that this is intended?

For context, this is actually causing issues for me as I used to use an environment variable to trigger certain actions. As such, I would like to know if this is intended or not so I can adjust my GitHub workflows accordingly.

[Alexhuszagh]

Update: See the comment below.

I believe so, since we changed our internal logic for how we handled [build] and [target.(...)] logic. See #773 and #781. This was considered a bug fix, and therefore not breaking, since the old behavior seemed incorrect. I'll check carefully with verbose just to be sure though.

Just some extra information below, just to ensure you have the available information to update your actions. We also allow you to provide default values for passthrough variables and volumes (see #748), and that should be everything covering config sources. If you use both Cargo.toml and Cross.toml, the values in Cross.toml will override Cargo.toml ones, and we merge into tables, and anything else (including arrays) will be overridden.

Let me double check though.

[Alexhuszagh]

This is a bug. I've filed #863. I'll document the expected behavior in the wiki once this is patched. We;ll probably need a 0.2.3 release then.

[Alexhuszagh]

#863 has been merged, and I've documented the expected behavior above. We should be doing another patch release with the fixes here.