Unusupported os in target when running inside devenv.sh

[byrnedo]

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

Describe your issue

When I run within devenv, rustc --print sysroot points to /nix/store/h9dd5l5zqf7yzyjbyb2895mwgaxbq0vp-rust-mixed

This seems to throw off cross, and I get the following error when trying to compile anything

cross -v build  --target aarch64-unknown-linux-gnu --release --locked
+ cargo metadata --format-version 1 --filter-platform aarch64-unknown-linux-gnu
[cross] warning: Found conflicting cross configuration in `/Users/doby/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/getrandom-0.3.2/Cargo.toml`, use `[workspace.metadata.cross]` in the workspace manifest instead.
Currently only using configuration from `/Users/doby/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/getrandom-0.2.15/Cargo.toml`
+ rustc --print sysroot
Error: 
   0: could not determine os in target triplet
   1: unsupported os in target, abi: "mixed", system: "rust" 

Location:
   src/docker/image.rs:342

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

0.2.5 (4090bec 2024-10-15)

Example

No response

Additional information / notes

No response