I put this in my Cargo.toml
[build]
target-dir = "../my-target"
However, Cargo doesn't recognize this key.
cargo run --release --bin my_project
warning: unused manifest key: build
error: failed to open: /.../project-root/target/releases/.cargo-lock
Caused by:
Permission denied (os error 13)
The custom target dir with the environment variable works:
CARGO_TARGET_DIR=../my-target cargo run --bin my_project
but how can I specify '../my-target' in Cargo.toml?
[build] is a Cargo-level configuration rather than for the project:
This document will explain how Cargo’s configuration system works, as well as available keys or configuration. For configuration of a project through its manifest, see the manifest format.
Put your [build] inside $PROJECT_DIR/.cargo/config or even $HOME/.cargo/config. See the above link for all the options.
Use the CARGO_TARGET_DIR environment variable:
CARGO_TARGET_DIR=../my-target cargo run --bin my_project
(This is stated in the question, but I wanted to highlight it for anyone that skips over that)
Related
I want to find a way to pass rustflags to artifact dependency bin.
Below is the story.
I write my toy OS currently, and using artifact dependency because this is suggested at rust-osdev/bootloader repositiory(descriptions are Booting section of this README) and I thought this is a useful way. However, I find that this way seems not to pass rustflags I attached in .cargo/config.toml in my kernel workspace like below.
[build]
target = "x86_64-unknown-none"
rustflags = ["-C", "relocation-model=static", "-C", "link-arg=-no-pie"]
[unstable]
build-std = ["core", "compiler_builtins"]
build-std-features = ["compiler-builtins-mem"]
In above config, I expect that kernel elf type is EXEC, but actually, that type is DYN, i.e. I got PIE Elf file even though I write static and no pie flags.
I tried some patterns like below.
run cargo build directly in kernel workspace directory
set invalid rustflags like link-args=hoge and run cargo build in root project directory
As a result
non pie elf (Elf type is EXEC) is created with no errors.
no errors appeared while compile even if I run cargo clean before build.
That's why, I suspect the rustflags I wrote in .cargo/config.toml does not work when its workspace is treated as binary artifact dependency.
Reproduction code is here.
If there is a way to pass rustflags, please teach me.
Add your build.rs in workspace, <project root path>/<kernel workspace name>/build.rs in my case, and put script like below in it.
fn main() {
println!("cargo:rust-link-arg=-no-pie");
}
rust-gpu says:
Copy the rust-toolchain file to your project. (You must use the same version of Rust as rust-gpu.)
So I copied that file into my root getting rust-toolchain with contents:
# If you see this, run `rustup self update` to get rustup 1.23 or newer.
# NOTE: above comment is for older `rustup` (before TOML support was added),
# which will treat the first line as the toolchain name, and therefore show it
# to the user in the error, instead of "error: invalid channel name '[toolchain]'".
[toolchain]
channel = "nightly-2022-10-29"
components = ["rust-src", "rustc-dev", "llvm-tools-preview"]
# commit_hash = 9565dfeb4e6225177bbe78f18cd48a7982f34401
# Whenever changing the nightly channel, update the commit hash above, and make
# sure to change REQUIRED_TOOLCHAIN in crates/rustc_codegen_spirv/src/build.rs also.
Then I tried building by doing cargo-run, getting:
error: failed to run custom build command for `rustc_codegen_spirv v0.4.0-alpha.17 (https://github.com/EmbarkStudios/rust-gpu#fabcbd9c)`
Caused by:
process didn't exit successfully: `/home/makogan/rust_never_engine/target/debug/build/rustc_codegen_spirv-b4185236522e0515/build-script-build` (exit status: 1)
--- stdout
cargo:rerun-if-env-changed=RUSTGPU_SKIP_TOOLCHAIN_CHECK
--- stderr
error: wrong toolchain detected (found commit hash `e631891f7ad40eac3ef58ec3c2b57ecd81e40615`, expected `9565dfeb4e6225177bbe78f18cd48a7982f34401`).
Make sure your `rust_toolchain` file contains the following:
-------------
[toolchain]
channel = "nightly-2022-10-29"
components = ["rust-src", "rustc-dev", "llvm-tools-preview"]
I am confused, the toolchain file says the same thing as the error message, what did I do wrong?
You're running a different version of nightly than the crate requires.
To check the version of cargo try to run cargo --version from within the project directory. If it shows anything else than the version you specified in the rust-toolchain file then you can try and check out the list below for possible fixes.
Make sure that:
The cargo you're using is managed by rustup if it is cargo +stable --version should show a version number and not an error.
The rust-toolchain is in the same directory as Cargo.toml if it's not copy or move it there.
There is no override on the crates directory. You can list them with rustup override list if the crate where the error appears is listed you can unset it with rustup override unset from within the crate root.
In this specific case 3. was the culprit.
I'm following the basic steps here: file:///Users/leongaban/.rustup/toolchains/stable-x86_64-apple-darwin/share/doc/rust/html/book/ch01-03-hello-cargo.html
I checked my cargo version, and cd .. back up to my root project folders and ran the following command to create a new project:
cargo new hello_cargo
And it threw the following error:
error: Failed to create package hello_cargo at /Users/leongaban/projects/rust_projects/hello_cargo
However when I run ls it did create the folder? So I'm curious how do I avoid that error in the future?
rust_projects % cargo new hello_cargo
error: Failed to create package `hello_cargo` at `/Users/leongaban/projects/rust_projects/hello_cargo`
Caused by:
could not find '/Users/leongaban/.git-templates/' to stat: No such file or directory; class=Os (2); code=NotFound (-3)
rust_projects % ls
hello_cargo hello_world
This maybe caused by git init command invoked when you run cargo new, the source code is as below:
if !path.join(".git").exists() {
// Temporary fix to work around bug in libgit2 when creating a
// directory in the root of a posix filesystem.
// See: https://github.com/libgit2/libgit2/issues/5130
paths::create_dir_all(path)?;
GitRepo::init(path, config.cwd())?;
}
And the .git-templates is documented under git init TEMPLATE DIRECTORY section.
The template directory will be one of the following (in order):
the argument given with the --template option;
the contents of the $GIT_TEMPLATE_DIR environment variable;
the init.templateDir configuration variable; or
the default template directory: /usr/share/git-core/templates.
So you should check above 4 possible cause to setup the non-exists folder '/Users/leongaban/.git-templates/' as git tempalte dir when run git init.
I also had this problem. My environment:
System: MacOS Catalina (version: 10.15.7)
Rustc version: rustc 1.51.0
Solution:
rustup self install
curl https://sh.rustup.rs -sSf | sh
I had a template defined in my gitconfig
[init]
templatedir = /Users/johndye/.git-templates
I am not sure when this got added or why but commenting it out got me past this error
I have a basic rust/cargo project with a single main file and some basic dependencies. The cargo build command works fine when the target is not specified (I am using windows so it builds to windows), but when I try to cross compile the program to linux using cargo build --target=x86_64-unknown-linux-gnu or cargo build --target=x86_64-unknown-linux-musl, the process fails with the following error: linker 'cc' not found.
Does anyone have an idea how to get around this? Is there a specific linker I need to install?
Thanks.
I've just figured it out.
It turns out you need to tell cargo to use the LLVM linker instead. You do this by creating a new directory called .cargo in your base directory, and then a new file called config.toml in this directory. Here you can add the lines:
[target.x86_64-unknown-linux-musl]
rustflags = ["-C", "linker-flavor=ld.lld"]
Then building with the command cargo build --target=x86_64-unknown-linux-musl should work!
I tried to make 'Hello World' in Rust using this tutorial, but the build command is a bit verbose:
cargo +nightly build --target wasm32-unknown-unknown --release
Is it possible to set the default target for cargo build?
You could use a Cargo configuration file to specify a default target-triple for your project. In your project's root, create a .cargo directory and a config.toml file in it with the following contents:
[build]
target = "wasm32-unknown-unknown"
As listed in the Cargo documentation, you can create a .cargo/config and specify the target:
[build]
target = "my-custom-target"
If you're able to use unstable features, following documentation and especially per-package-target feature add this to you crate manifest that usually named Cargo.toml
cargo-features = ["per-package-target"]
[package]
forced-target = "wasm32-unknown-unknown"
# and/or:
default-target = "wasm32-unknown-unknown"
This requires nightly toolchain.