You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: git.rs
    path of file: ./repos/embuild/src
    
    the code of the file until where you have to start completion: //! Git repository manipulation through the git CLI.
// TODO: maybe use `git2` crate

use std::ffi::OsStr;
use std::fmt::Display;
use std::num::NonZeroU64;
use std::path::{Path, PathBuf};

use anyhow::{anyhow, Context};

use crate::cmd;
use crate::cmd::CmdError;
use crate::utils::PathExt;

/// The git command.
pub const GIT: &str = "git";

/// A list of environment variables to set/unset so that git is guaranteed to output
/// english.
///
/// Note: `LANGUAGE` must be unset, otherwise it will override `LC_ALL` if it is set to
/// anything other than `C` (we use `C.UTF-8`).
c
    
    pub fn open(dir: impl AsRef<Path>) -> anyhow::Result<Repository> {
        let dir = dir.as_ref();
        let base_err = || anyhow::anyhow!("'{}' is not a git respository", dir.display());

        let top_level_dir =
            cmd!(GIT, "rev-parse", "--show-toplevel"; current_dir=(dir), envs=(LC_ALL))
                .stdout()
                .context(base_err())?;
        let top_level_dir = Path::new(&top_level_dir)
            .canonicalize()
            .context(base_err())?;

        if !dir
            .canonicalize()
            .map(|p| p.eq(&top_level_dir))
            .unwrap_or(false)
        {
            return Err(base_err());
        }

        let git_dir = Path::new(
            &cmd!(GIT, "rev-parse", "--git-dir"; current_dir=(dir), envs=(LC_ALL)).stdout()?,
        )
        .abspath_relative_to(dir);

        Ok(Repository {
            git_dir,
            worktree: dir.to_owned(),
            remote_name: None,
        })
    }