使用 Xargo 从特定来源编译 `core`

Question

Based on this comment，应该可以使用 Xargo 来管理特定目标的自定义 core crate 的安装。我已经尝试了以下方法来让它与一个除了 core:

没有其他依赖的板条箱一起工作

Cargo.toml: 没有列出依赖项

[package]
name = "chip8-engine"
version = "0.1.0"
authors = ["Dr. ERDI Gergo <gergo@erdi.hu>"]

[dependencies]

Xargo.toml：我为 core

列出的具体来源

[target.avr-atmel-none.dependencies]
core = { git = "https://github.com/gergoerdi/rust-avr-libcore-mini", rev = "adda44aa91ac517aab6915447592ee4cad26564c" }

但是，通过 xargo build 构建失败，就好像我只是使用 cargo:

$ ~/.cargo/bin/xargo build --release -v --target avr-atmel-none
+ "rustc" "--print" "sysroot"
+ "cargo" "build" "--release" "-v" "--target" "avr-atmel-none"
   Compiling chip8-engine v0.1.0 (file:///home/cactus/prog/rust/avr/chip8-engine-avr)
     Running `stage1/bin/rustc --crate-name chip8_engine src/lib.rs --crate-type lib -C opt-level=3 -C metadata=231962fc6e1bee04 -C extra-filename=-231962fc6e1bee04 --out-dir /home/cactus/prog/rust/avr/chip8-engine-avr/target/avr-atmel-none/release/deps --emit=dep-info,link --target avr-atmel-none -L dependency=/home/cactus/prog/rust/avr/chip8-engine-avr/target/avr-atmel-none/release/deps -L dependency=/home/cactus/prog/rust/avr/chip8-engine-avr/target/release/deps`
error[E0463]: can't find crate for `core`
  |
  = note: the `avr-atmel-none` target may not be installed

error: aborting due to previous error

error: Could not compile `chip8-engine`.

Caused by:
  process didn't exit successfully: `stage1/bin/rustc --crate-name chip8_engine src/lib.rs --crate-type lib -C opt-level=3 -C metadata=231962fc6e1bee04 -C extra-filename=-231962fc6e1bee04 --out-dir /home/cactus/prog/rust/avr/chip8-engine-avr/target/avr-atmel-none/release/deps --emit=dep-info,link --target avr-atmel-none -L dependency=/home/cactus/prog/rust/avr/chip8-engine-avr/target/avr-atmel-none/release/deps -L dependency=/home/cactus/prog/rust/avr/chip8-engine-avr/target/release/deps` (exit code: 101)

请注意，没有任何迹象表明甚至尝试了 Git 流量。

相比之下，如果我将我的 core = { git = ...} 行放在 Cargo.toml 而不是 Xargo.toml 中，这是 vanilla cargo 的输出，它按预期工作：

$ cargo build -v --target=avr-atmel-none --release
   Compiling core v0.1.0 (https://github.com/gergoerdi/rust-avr-libcore-mini?rev=adda44aa91ac517aab6915447592ee4cad26564c#adda44aa)
     Running `stage1/bin/rustc --crate-name core /home/cactus/.cargo/git/checkouts/rust-avr-libcore-mini-37e279d93a70b45a/adda44a/src/lib.rs --crate-type lib -C opt-level=3 -C metadata=47f38a1987c5b284 -C extra-filename=-47f38a1987c5b284 --out-dir /home/cactus/prog/rust/avr/chip8-engine-avr/target/avr-atmel-none/release/deps --emit=dep-info,link --target avr-atmel-none -L dependency=/home/cactus/prog/rust/avr/chip8-engine-avr/target/avr-atmel-none/release/deps -L dependency=/home/cactus/prog/rust/avr/chip8-engine-avr/target/release/deps --cap-lints allow`
   Compiling chip8-engine v0.1.0 (file:///home/cactus/prog/rust/avr/chip8-engine-avr)
     Running `stage1/bin/rustc --crate-name chip8_engine src/lib.rs --crate-type lib -C opt-level=3 -C metadata=231962fc6e1bee04 -C extra-filename=-231962fc6e1bee04 --out-dir /home/cactus/prog/rust/avr/chip8-engine-avr/target/avr-atmel-none/release/deps --emit=dep-info,link --target avr-atmel-none -L dependency=/home/cactus/prog/rust/avr/chip8-engine-avr/target/avr-atmel-none/release/deps -L dependency=/home/cactus/prog/rust/avr/chip8-engine-avr/target/release/deps --extern core=/home/cactus/prog/rust/avr/chip8-engine-avr/target/avr-atmel-none/release/deps/libcore-47f38a1987c5b284.rlib`
    Finished release [optimized] target(s) in 15.21 secs

Answer 1

您可能需要安装 nightly Rust 工具链以允许 xargo 为您的目标构建一些支持代码。我必须做一些类似的事情才能让嵌入式 ARM 设置与 xargo 一起工作。在嵌入式目标的目录中执行此操作：

$ rustup install nightly
$ rustup component add rust-src  # needed for xargo buildup of the target
$ rustup override set nightly    # sets the rustc version to run for this dir
$ xargo build

Answer 2

事实证明 picking up rustc's path from .cargo/config is not currently supported by Xargo，因此无论我想使用什么 rustc，都需要安装为 rustup link。引用以上票：

In the meantine you could use rustup to create a custom toolchain that points to your stage1 rustc. That's known to work.
$ cd /home/cactus/prog/rust/rust-avr/build/build/x86_64-unknown-linux-gnu/stage1
$ rustup toolchain link avr-toolchain .
$ rustup default avr-toolchain
$ rustc -V
# should say dev channel

使用 Xargo 从特定来源编译 `core`

Compiling `core` from a specific source using Xargo

embedded

rust

rust-crates

rust-cargo