run-llama/liteparse · error

HOME env var not set

Error message

HOME env var not set

What it means

dirs_cache in pdfium-sys's build script resolves the user's cache root: on non-Windows platforms it reads HOME and panics with this message when the variable is unset. It then appends Library/Caches (macOS) or .cache (other Unix) to build the pdfium download cache path.

Solutions

1. Export HOME before building (e.g. HOME=/home/builduser cargo build).
2. In Docker, set ENV HOME=/home/user for the build stage or pass -e HOME in the run command.
3. Set the pdfium cache directory explicitly if the crate supports an override env var, bypassing dirs_cache.
4. Pre-seed the pdfium cache so no download/cache resolution is needed.

Example fix

// before: Dockerfile build step without HOME
USER app
RUN cargo build --release

// after
USER app
ENV HOME=/home/app
RUN cargo build --release

# Shell preflight before cargo build
[ -n "$HOME" ] || { echo "HOME is not set"; exit 1; }

When it happens

Trigger: Running `cargo build` on Linux/macOS with HOME unset or empty — e.g. cargo invoked from a systemd unit, a Docker container running as a non-root user without -e HOME, an SSH command with a sanitized environment, or a build service that strips env vars.

Common situations: Docker builds with `USER nonroot` but no HOME set; cron/systemd jobs lacking a login environment; CI containers where the build tool sanitizes the environment; Nix or chroot setups without a profile.

Understand the failure class

Background: "environment variable is not set" and "Missing keys in environment" errors: what missing required env var messages mean and how to fix them — this error's family across 28 libraries.

Related errors

• USERPROFILE env var not set
• failed to create temp dir
• failed to extract pdfium archive
• failed to move pdfium to cache dir
• WASI proc_exit called with code

AI-assisted analysis of run-llama/liteparse@22d2dd8cd7 (2026-09-08). Data as JSON: /api/errors/7a0e30300aebdb51. Report an issue: GitHub.

Appendix: source

Thrown at crates/pdfium-sys/build.rs:138

}

fn dirs_cache() -> PathBuf {
    if let Ok(xdg) = env::var("XDG_CACHE_HOME") {
        return PathBuf::from(xdg);
    }

    let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap_or_default();

    // Windows -> USERPROFILE
    if target_os == "windows" {
        if let Ok(local_app_data) = env::var("LOCALAPPDATA") {
            return PathBuf::from(local_app_data);
        }
        let home = env::var("USERPROFILE").expect("USERPROFILE env var not set");
        return PathBuf::from(home).join("AppData\\Local");
    }

    let home = env::var("HOME").expect("HOME env var not set");
    if target_os == "macos" {
        PathBuf::from(&home).join("Library/Caches")
    } else {
        PathBuf::from(&home).join(".cache")
    }
}

/// Map target triple to the pdfium-binaries asset name (without .tgz).
fn pdfium_asset_stem() -> &'static str {
    let target = env::var("TARGET").unwrap();
    match target.as_str() {
        "aarch64-apple-darwin" => "pdfium-mac-arm64",
        "x86_64-apple-darwin" => "pdfium-mac-x64",
        // Universal macOS binary works for both, but we prefer arch-specific
        "x86_64-unknown-linux-gnu" => "pdfium-linux-x64",
        "x86_64-unknown-linux-musl" => "pdfium-linux-musl-x64",
        "aarch64-unknown-linux-gnu" | "aarch64-unknown-linux-musl" => "pdfium-linux-arm64",
        "armv7-unknown-linux-gnueabihf" => "pdfium-linux-arm",

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