vosen/ZLUDA · error

Failed to read {}: {}

Error message

Failed to read {}: {}

What it means

ptx build-script panic in check_lfs_file: opening the .bc file succeeded but reading the 2-byte magic header failed. Since only 2 bytes are requested, this indicates a zero-length file or an I/O error — most commonly an aborted LFS smudge leaving an empty or unreadable file for lib/zluda_ptx_impl*.bc.

Source

Thrown at ptx/build.rs:18

use std::fs::File;
use std::io::Read;

fn main() {
    let bc_path = "lib/zluda_ptx_impl.bc";
    let bc_constrained_path = "lib/zluda_ptx_impl_constrained.bc";
    println!("cargo:rerun-if-changed={}", bc_path);
    println!("cargo:rerun-if-changed={}", bc_constrained_path);
    check_lfs_file(bc_path);
    check_lfs_file(bc_constrained_path);
}

fn check_lfs_file(bc_path: &str) {
    let mut magic = [0u8; 2];
    File::open(bc_path)
        .unwrap_or_else(|e| panic!("Failed to open {}: {}", bc_path, e))
        .read_exact(&mut magic)
        .unwrap_or_else(|e| panic!("Failed to read {}: {}", bc_path, e));
    assert!(
        &magic == b"BC",
        "{} is a git lfs stub and not the actual file. Run `git lfs pull` to fetch it",
        bc_path
    );
}

View on GitHub (pinned to 9c8b43f242)

Solutions

1. Check that the .bc file is not zero-length; re-pull with `git lfs pull` if it is
2. Ensure the file is a regular file with read permissions
3. Retry the build after fixing LFS hooks (`git lfs install`)

When it happens

Trigger: Thrown at ptx/build.rs:18 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of vosen/ZLUDA@9c8b43f242 (2026-09-06). Data as JSON: /api/errors/803041165f5ff06b. Report an issue: GitHub.