Mounting Volumes for Local Out-of-Tree Dependencies

A simple example of using Cross.toml with volumes to ensure the project directory is mounted.

We assume a project directory analogous to the following, where we have a directory containing numerous independent crates (lib1, lib2, lib3) used as local dependencies for another crate (bin).

project/
    lib1/
        Cargo.toml
    lib2/
        Cargo.toml
    lib3/
        Cargo.toml
    bin/
        Cargo.toml

First, we create a library (local_lib) and a binary (binary) that relies on that library:

Cargo.toml

[dependencies]
local_lib = { path = "../local_lib" }

Next, we ensure that the directory provided by PROJECT_DIR is mounted:

Cross.toml

[build.env]
volumes = [
    "PROJECT_DIR",
]

And finally, we write a simple wrapper around cross to ensure we define PROJECT_DIR:

cross.sh

#!/bin/bash
PROJECT_DIR=.. exec cross $@

Building the project works with:

git clone https://github.com/Alexhuszagh/cross_issue405
cd cross_issue405/binary
 ./cross.sh run --target powerpc64le-unknown-linux-gnu