如何在通过交叉运行Rust时发送RUST_BACKTRACE=1

Question

我正在尝试交叉编译使用交叉的Rust项目

我得到了一个错误，我希望通过设置环境变量RUST_BACKTRACE=1来跟踪进程。

但我不知道如何在使用交叉时做到这一点。

编辑

我使用的是命令cross build --target aarch64-unknown-linux-gnu

这是我的“cross.toml”内容

[target.aarch64-unknown-linux-gnu]
openssl-sys = "0.9.76"

[build.env]
passthrough = [
    "RUST_BACKTRACE",
    "RUST_LOG",
    "TRAVIS",
]

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

在试图编译时，我得到了以下错误

 thread 'main' panicked at '

  Could not find directory of OpenSSL installation, and this `-sys` crate cannot
  proceed without this knowledge. If OpenSSL is installed and this crate had
  trouble finding it,  you can set the `OPENSSL_DIR` environment variable for the
  compilation process.

  Make sure you also have the development packages of openssl installed.
  For example, `libssl-dev` on Ubuntu or `openssl-devel` on Fedora.

  If you're in a situation where you think the directory *should* be found
  automatically, please open a bug at https://github.com/sfackler/rust-openssl
  and include information about your system as well as this message.

  $HOST = x86_64-unknown-linux-gnu
  $TARGET = aarch64-unknown-linux-gnu
  openssl-sys = 0.9.76

  ', /cargo/registry/src/github.com-1ecc6299db9ec823/openssl-sys-0.9.76/build/find_normal.rs:191:5
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Answer 1

在passthrough中使用Cross.toml只是传递本地环境变量。因此，在您的示例中，它按预期工作，但是它没有按您的要求工作，原因是没有设置RUST_BACKTRACE变量。

在Linux/Unix (mac)中，您可以通过编写echo $RUST_BACKTRACE和编写RUST_BACKTRACE=1临时设置环境的值。

因此，为了在交叉中设置变量，可以在运行命令时设置RUST_BACKTRACE，如下所示：

RUST_BACKTRACE=1 cross build --target aarch64-unknown-linux-gnu

也可以在Cross.toml配置中直接设置值，如下所示：

[target.aarch64-unknown-linux-gnu]
openssl-sys = "0.9.76"

[build.env]
passthrough = [
    "RUST_BACKTRACE=1",
    "RUST_LOG",
    "TRAVIS",
]

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