Run `CARGO_TARGET_DIR=$PWD/target/tauri cargo build -p but`

Error message

Run `CARGO_TARGET_DIR=$PWD/target/tauri cargo build -p but` to build the `but` binary

What it means

Before creating or repairing the /usr/local/bin/but symlink, the installer verifies the built CLI binary exists at the expected Tauri target-dir path. If the `but` crate was never compiled into $PWD/target/tauri, it bails with the exact build command to run (crates/but-action/src/cli.rs:116).

Source

Thrown at crates/but-action/src/cli.rs:116

        }
    } else {
        Err(anyhow!(
            "Would probably need to run \"ln -sf '{}' '{UNIX_LINK_PATH}'\"{privilege}",
            cli_path.display(),
            privilege = if can_elevate_privileges {
                " with root permissions"
            } else {
                ""
            }
        ))
    }
}

fn ensure_cli_path_exists_prior_to_link(cli_path: &std::path::Path) -> anyhow::Result<()> {
    if cli_path.exists() {
        return Ok(());
    }
    bail!("Run `CARGO_TARGET_DIR=$PWD/target/tauri cargo build -p but` to build the `but` binary")
}

/// On Windows, we'll provide helpful instructions rather than attempt automatic installation
/// since:
/// 1. Creating symlinks requires developer mode or admin privileges
/// 2. There's no standard user-writable directory that's always in PATH
/// 3. Users typically add directories to PATH manually on Windows
///
/// Note that this isn't usually called on Windows.
#[cfg(windows)]
fn install_cli_windows(cli_path: std::path::PathBuf) -> anyhow::Result<()> {
    let but_filename = cli_path
        .file_name()
        .context("BUG: encountered but CLI path without /")?;

    bail!(
        "Automatic CLI installation is not supported on Windows.\n\
        \n\

View on GitHub (pinned to caf1f223d3)

Solutions

From the repository root run `CARGO_TARGET_DIR=$PWD/target/tauri cargo build -p but`, then retry the install
Verify the binary exists at the path reported by get_cli_path() before retrying
If the target dir was moved, rebuild so the binary lands at the expected location

Example fix

# before: install CLI from the app -> bail: 'Run `CARGO_TARGET_DIR=$PWD/target/tauri cargo build -p but`...'
# after:
$ cd <repo-root>
$ CARGO_TARGET_DIR=$PWD/target/tauri cargo build -p but
$ # retry the install action; symlink is now created

Defensive patterns

Strategy: validation

Validate before calling

// Verify the built binary exists before install
let cli_path = get_cli_path()?;
if !cli_path.exists() {
    // run: CARGO_TARGET_DIR=$PWD/target/tauri cargo build -p but
    anyhow::bail!("build the but binary first: CARGO_TARGET_DIR=$PWD/target/tauri cargo build -p but");
}
do_install_cli(mode)?;

Prevention

Make `cargo build -p but` (with the Tauri CARGO_TARGET_DIR) part of the dev setup script
Never run cargo clean between building the CLI and installing the link
In CI, assert the CLI artifact exists before the install step

When it happens

Trigger: Invoking the desktop app's 'install CLI' action (do_install_cli / ensure_cli_path_exists_prior_to_link) on a dev checkout where `cargo build -p but` was never run with CARGO_TARGET_DIR=$PWD/target/tauri, or where the target dir was cleaned/moved.

Common situations: Fresh clone after a clean/build step that skips the Rust CLI; running the app from a build that did not bundle the CLI; CI artifacts assembled without the but binary; cargo clean before installing.

Related errors

AI-assisted analysis of gitbutlerapp/gitbutler@caf1f223d3 (2026-08-20). Data as JSON: /api/errors/2415604f89158008. Report an issue: GitHub.