Incorrect Parsing of Arrays in Config Files

[Alexhuszagh]

Checklist

• I've looked through the issues and pull requests for similar reports

Describe your issue

If providing arrays in [build.env], they don't seem to be used correctly. For example, the following config files:

Case 1

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

Case 2

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

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

Case 3

[build.env]
passthrough = []

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

When compiling with CARGO_TERM_COLOR=never cross build --target aarch64-unknown-linux-gnu, we should expect CARGO_TERM_COLOR to passthrough in all cases, but it only does in the last one. We'd expect in case 2 and 3 for the arrays to merge, and in 1 for it to only use the passthrough in [build.env]. It seems to ignore case 1 and 2 though.

What target(s) are you cross-compiling for?

No response

Which operating system is the host (e.g computer cross is on) running?

• macOS
• Windows
• Linux / BSD
• other OS (specify in description)

What architecture is the host?

• x86_64 / AMD64
• arm32
• arm64 (including Mac M1)

What container engine is cross using?

• docker
• podman
• other container engine (specify in description)

cross version

cross 0.2.2

Example

No response

Additional information / notes

No response

[Alexhuszagh]

We also need to add unittests for this to avoid further regressions.

[Emilgardis]

In case two, I don't think it should merge/work

[Alexhuszagh]

In case two, I don't think it should merge/work

Hmmm, I think that would be a breaking change because we have the sum of the values, correct? Maybe something to change in 0.3.

cross/src/config.rs

Lines 303 to 329 in 48d2b7b

	fn sum_of_env_toml_values<'a>(
	&'a self,
	env_values: Option<impl AsRef<[String]>>,
	toml_getter: impl FnOnce(&'a CrossToml) -> (Option<&'a [String]>, Option<&'a [String]>),
	) -> Result<Option<Vec<String>>> {
	let mut defined = false;
	let mut collect = vec![];
	if let Some(vars) = env_values {
	collect.extend(vars.as_ref().iter().cloned());
	defined = true;
	} else if let Some((build, target)) = self.toml.as_ref().map(toml_getter) {
	if let Some(build) = build {
	collect.extend(build.iter().cloned());
	defined = true;
	}
	if let Some(target) = target {
	collect.extend(target.iter().cloned());
	defined = true;
	}
	}
	if !defined {
	Ok(None)
	} else {
	Ok(Some(collect))
	}
	}
	}

[Alexhuszagh]

It looks like env.passthrough is set to true too (but the rest are false):

cross/src/config.rs

Lines 250 to 257 in 48d2b7b

	pub fn env_passthrough(&self, target: &Target) -> Result<Option<Vec<String>>> {
	self.vec_from_config(
	target,
	Environment::passthrough,
	CrossToml::env_passthrough,
	true,
	)
	}

[Emilgardis]

hmm, I guess we need a better way to flag that that nothing should be inherited for arrays, for now I think it's fine to keep the correct behaviour (i.e all cases should work as described)

the issue is that arrays can be null, empty or filled. Strings and booleans are null or filled.

[Alexhuszagh]

I've fixed all of the above in #867, and added comprehensive unittests to ensure the regression does not reoccur. In v0.3.0, we can set it so they don't merge.