Config in Cargo.toml: invalid type: map, expected a string for key target.x86_64-unknown-freebsd.image

[n8henrie]

Checklist

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

Describe your issue

Related: #657

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

x86_64-unknown-freebsd

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 0.2.4

Example

$ cargo new foo && cd $_
$ cat <<'EOF' >> Cargo.toml
[package.metadata.cross.target.x86_64-unknown-freebsd]
image.name = "ghcr.io/cross-rs/x86_64-unknown-freebsd:local"
image.toolchain = ["linux/arm64/v8=aarch64-unknown-linux-gnu"]
EOF
$ cross build --target x86_64-unknown-freebsd --release

Using cross 0.2.4 from nixpkgs or crates.io, I get:

Error:
   0: invalid type: map, expected a string for key `target.x86_64-unknown-freebsd.image`

Using cross from main, I get a different error:

$ cargo install cross --git https://github.com/cross-rs/cross
$ cross --version
cross 0.2.4 (1d9d310 2023-01-05)
$ cross build --target x86_64-unknown-freebsd --release
Error:
   0: invalid type: string "linux/arm64/v8=aarch64-unknown-linux-gnu", expected a borrowed string for key `target.x86_64-unknown-freebsd.image.toolchain`

Location:
   src/cross_toml.rs:181

If I instead put (what I believe to be) the analogous table into Cross.toml, I get the same error with nixpkgs and crates.io but it works fine from main:

$ cat <<'EOF' > Cross.toml
[target.x86_64-unknown-freebsd]
image.name = "ghcr.io/cross-rs/x86_64-unknown-freebsd:local"
image.toolchain = ["linux/arm64/v8=aarch64-unknown-linux-gnu"]
EOF
$ cross --version
cross 0.2.4 (1d9d310 2023-01-05)
[cross] warning: `cross` does not provide a Docker image for target aarch64-apple-darwin, specify a custom image in `Cross.toml`.
[cross] note: Falling back to `cargo` on the host.
cargo 1.66.0 (d65d197ad 2022-11-15)
$ cross build --target x86_64-unknown-freebsd --release
   Compiling foo v0.1.0 (/private/var/folders/kb/tw_lp_xd2_bbv0hqk4m0bvt80000gn/T/tmp.ililnMNd9D/foo)
    Finished release [optimized] target(s) in 8.52s

Using the current main, as recommended in the README, is it expected that this table works from Cross.toml but not from Cargo.toml?

Thanks for your work on a cool project!

Additional information / notes

No response

[Emilgardis]

This should work in Cargo.toml, the issue is how we're doing the deserialization

cross/src/cross_toml.rs

Line 177 in 1d9d310

D: Deserializer<'de>,

and

cross/src/docker/image.rs

Line 108 in 1d9d310

#[serde(try_from = "&str")]

[Emilgardis]

Alright, that was wrong, it's a bit more "wierd".

When merging, we create a CrossToml from the metadata here:

cross/src/cross_toml.rs

Line 213 in 1d9d310

serde_json::from_value(value)

this works fine in most cases, however, when the serialization does not match the deserialization, this fails when they do not match (i.e it can be either a toml string or array).

Solution is to serialize

cross/src/docker/image.rs

Lines 104 to 117 in 1d9d310

	/// The architecture/platform to use in the image
	///
	/// https://github.com/containerd/containerd/blob/release/1.6/platforms/platforms.go#L63
	#[derive(Debug, Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
	#[serde(try_from = "&str")]
	pub struct ImagePlatform {
	/// CPU architecture, x86_64, aarch64 etc
	pub architecture: Architecture,
	/// The OS, i.e linux, windows, darwin
	pub os: Os,
	/// The platform variant, i.e v8, v7, v6 etc
	pub variant: Option<String>,
	pub target: TargetTriple,
	}

as a string

[n8henrie]

Wow, super fast fix. Thank you!

After putting the config back in Cargo.toml it builds

$ rm -f Cross.toml
$ cargo install cross --git https://github.com/Emilgardis/cross --branch fix-1182
$ cross --version
cross 0.2.4 (6a57d01 2023-01-06)
[cross] warning: `cross` does not provide a Docker image for target aarch64-apple-darwin, specify a custom image in `Cross.toml`.
[cross] note: Falling back to `cargo` on the host.
cargo 1.66.0 (d65d197ad 2022-11-15)
$ cross build --target x86_64-unknown-freebsd --release
    Finished release [optimized] target(s) in 1.41s
$ file target/x86_64-unknown-freebsd/release/hello-world-pfsense
target/x86_64-unknown-freebsd/release/hello-world-pfsense: ELF 64-bit LSB pie executable, x86-64, version 1 (FreeBSD), dynamically linked, interpreter /libexec/ld-elf.so.1, for FreeBSD 12.4, FreeBSD-style, stripped
$ scp target/x86_64-unknown-freebsd/release/hello-world-pfsense router:/tmp
hello-world-pfsense                                                                                                                                                                                         100%  275KB   1.4MB/s   00:00
$ ssh router /tmp/hello-world-pfsense
Hello, world!

I'm not sure about the warning (EDIT: I guess it's just a warning, probably not be a good idea to have it try to parse the config in order to silence the warning in a version check), but it seems to work!

[n8henrie]

This error is back.

$ tail -n 3 Cargo.toml 
[package.metadata.cross.target.x86_64-unknown-freebsd]
image.name = "ghcr.io/cross-rs/x86_64-unknown-freebsd:local"
image.toolchain = ["linux/arm64/v8=aarch64-unknown-linux-gnu"]
$ cross --version
cross 0.2.5
Error: 
   0: invalid type: map, expected a string for key `target.x86_64-unknown-freebsd.image`

Based on the docs it looks like image.name and image.toolchain are still supported configuration values.

EDIT: Only getting this from crates.io, installing from git seems to work.