How to get git hash in build.rs ?

[enomado]

Hi

Here is my Cross.toml

[target.x86_64-pc-windows-gnu]
pre-build = [
    "dpkg --add-architecture $CROSS_DEB_ARCH",
    "apt update",
    # tls
    "apt install --assume-yes nasm",
    # protobuf
    "apt install --assume-yes protobuf-compiler:$CROSS_DEB_ARCH",
    "apt install --assume-yes openssl",
    "apt install --assume-yes git",
    
]

I'm trying

    let hash = Command::new("git").args(&["rev-parse", "HEAD"]).output()?;
    let git_hash = String::from_utf8(hash.stdout)?;

    p!("BUILD.rs -> git hash ...{}", git_hash);

It emits empty string.

I also tried vergen_git2 and apt install --assume-yes libgit2, but result is pretty the same - it cant find repo, or so.

[Emilgardis]

Im guessing theres some output in stderr? This is probably a file ownership problem. If it is, see #1473 (reply in thread)

[enomado]

Looks like a found a problem.

stderr was fatal: not a git repository (or any parent up to mount point /home/sc/t/bur)

real problem was what my repo is not equal to workspace root.
I have something like

git_repo
    .git
    my_rust_project

when I run cross build, my pwd is git_repo/my_rust_project, so I have mounted only my_rust_project, and ./../.git is not accessible.

Is there any way to set mount point as ./../, or should I reorganize my repository?

[enomado]

looks like I found an answer #1294

But i cant get how lets say FTL_DIR can help me

[enomado]

got it

it'll be mounted in the container at the same path as on the host.

[merklefruit]

Hi @enomado could you share your [build.env] section of Cross.toml? I'm running into the same issue :)

[enomado]

@merklefruit its still experimental, but last time worked

[build.env]
# i'm in /home/sc/t/bur/rust_app
volumes = [
    # "A_DIRECTORY=/home/sc/t/bur",
    "A_DIRECTORY=./../",
]

[target.x86_64-pc-windows-gnu]

# image = "ghcr.io/cross-rs/aarch64-unknown-linux-gnu:0.2.4"

# build-std = ["core", "alloc"] 

pre-build = [
    "dpkg --add-architecture $CROSS_DEB_ARCH",
    "apt update",
    # for tls
    "apt install --assume-yes nasm",
    # for protobuf
    "apt install --assume-yes protobuf-compiler:$CROSS_DEB_ARCH",
    "apt install --assume-yes openssl",
    "apt install --assume-yes git",

    # some of them need gfor git yo work
    "git config --system --add safe.directory '*'",
    "git config --system --add safe.directory './../*'",
    "git config --system --add safe.directory './../../*'",
    "git config --system --add safe.directory './../../../*'",
    "git config --system --add safe.directory './../../../../*'",
    "git config --system --add safe.directory './../../../../../*'",
    
]

build.rs

#![allow(dead_code)]

use std::{env, fs, path::PathBuf, process::Command, str::FromStr};

use vergen_git2::{Emitter, Git2Builder};

// use vergen::Emitter;

extern crate winresource;

// use vergen::*;

fn main() {
    if std::env::var("CARGO_CFG_TARGET_OS").unwrap() == "windows" {
        let mut res = winresource::WindowsResource::new();
        res.set_icon("./assets/app_icon.ico");
        res.compile().unwrap();
    }

    // vergen(SHORT_SHA | COMMIT_DATE).unwrap();

    // works in cross https://github.com/cross-rs/cross/discussions/1473#discussioncomment-9128550
    gen_version_wrap();

    // get_version_dirty_way_wrap()
}

macro_rules! p {
    ($($tokens: tt)*) => {
        println!("cargo:warning={}", format!($($tokens)*))
    }
}

fn get_version_dirty_way_wrap() {
    match get_version_dirty_way() {
        Ok(_s) => {}
        Err(_x) => {}
    }
}

fn get_version_dirty_way() -> anyhow::Result<String> {
    let hash = Command::new("git").args(&["rev-parse", "HEAD"]).output()?;
    let git_hash = String::from_utf8(hash.stdout)?;
    let git_hash_err = String::from_utf8(hash.stderr)?;

    let pp = PathBuf::from_str("./../../../")?;

    let paths = fs::read_dir(pp).unwrap();

    for path in paths {
        let ppp = path.unwrap();
        p!("paths, {}", &ppp.path().display());
    }

    let path = PathBuf::from_str("./../../../.git/refs/heads/master")?;

    let contents = fs::read_to_string(path).unwrap();

    p!("BUILD.rs -> git hash2 {}", contents);

    p!(
        "BUILD.rs -> git hash {}, {}, {}...",
        git_hash,
        git_hash_err,
        contents
    );

    Ok(git_hash)
}

fn gen_version_wrap() {
    match gen_version() {
        Ok(_x) => {}
        Err(x) => {
            println!("failed to get git version. {x}")
        }
    }
}

fn gen_version() -> anyhow::Result<()> {
    // let build = BuildBuilder::all_build()?;
    // let git2 = Git2Builder::all_git()?;

    let _path = env::current_dir()?;

    // let repo = path.join("./../../../").canonicalize()?;

    // p!("BUILD.rs -> Starting ...{}", repo.display());
    // println!("The current directory is {}", path.display());

    // let git2 = GitclBuilder::all_git()?;
    let git2 = Git2Builder::all_git()?;
    // VERGEN_GIT_SHA
    // git2.at_path(repo);

    Emitter::default()
        // .add_instructions(&build)?
        .add_instructions(&git2)?
        .emit()?;

    Ok(())
}

main.rs

impl AppGitHash {
    pub fn get() -> Option<String> {
        let hash = option_env!("VERGEN_GIT_SHA");
        hash.map(|s| s[0..8].to_owned())
    }

    // VERGEN_GIT_SHA
}

[merklefruit]

Thank you!