[-Zbuild-std] Duplicate lang item with panic=abort

Open

#7,359 opened on Sep 13, 2019 10 comments 22 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

C-bug S-triage Z-build-std

Dominant language: Rust
Stars: 15.5k
Forks: 3k
Avg merge: 23h 30m
Merged PRs (30d): 51

Description

Combining a no-harness test with a panic=abort key in the Cargo.toml leads to duplicate lang item errors if compiled with cargo test -Zbuild-std=core.

Steps to Reproduce

MRE by @hoodmane from #15058

Make a folder with the following two files:

Cargo.toml

[package]
name = "test"
edition = "2024"

[profile.dev]
panic = "abort"

[[bin]]
name = "test"
path = "main.rs"

main.rs

pub fn main() { }

Bash

rustup install nightly-2025-01-13
cargo +nightly-2025-01-13 build -Zbuild-std

Result

   Compiling tmp v0.0.0 (/home/rchatham/Documents/programming/rust-wasm-eh-test-2)
error[E0152]: duplicate lang item in crate `core`: `sized`
  |
  = note: the lang item is first defined in crate `core` (which `std` depends on)
  = note: first definition in `core` loaded from /home/rchatham/Documents/programming/rust-wasm-eh-test-2/target/wasm32-unknown-emscripten/debug/deps/libcore-05cdacbb5559ef58.rlib, /home/rchatham/Documents/programming/rust-wasm-eh-test-2/target/wasm32-unknown-emscripten/debug/deps/libcore-05cdacbb5559ef58.rmeta
  = note: second definition in `core` loaded from /home/rchatham/.rustup/toolchains/nightly-2025-01-13-x86_64-unknown-linux-gnu/lib/rustlib/wasm32-unknown-emscripten/lib/libcore-9c3bca22b80bc54a.rlib

For more information about this error, try `rustc --explain E0152`.
error: could not compile `test` (bin "test") due to 1 previous error

Original MRE from the issue author

Create a new cargo project with the following contents:

Cargo.toml:

[package]
name = "playground"
version = "0.1.0"
authors = ["Philipp Oppermann <dev@phil-opp.com>"]
edition = "2018"

[lib]
harness = false

[dependencies]

[profile.dev]
panic = "abort"     # it works if this line is removed

src/lib.rs:

#![no_std]
#![cfg_attr(test, no_main)]

#[cfg(test)]
#[panic_handler]
fn panic(_info: &core::panic::PanicInfo) -> ! {
    loop {}
}

target.json:

{
    "llvm-target": "x86_64-unknown-none",
    "data-layout": "e-m:e-i64:64-f80:128-n8:16:32:64-S128",
    "arch": "x86_64",
    "target-endian": "little",
    "target-pointer-width": "64",
    "target-c-int-width": "32",
    "os": "none",
    "executables": true,
    "linker-flavor": "ld.lld",
    "linker": "rust-lld",
    "panic-strategy": "abort",
    "disable-redzone": true,
    "features": "-mmx,-sse,+soft-float"
  }

Run cargo test --target target.json -Z build-std=core --no-run

The following error occurs:

cargo test --target target.json -Z build-std=core
 Compiling playground v0.1.0 (…)
 error: duplicate lang item in crate `core`: `bool`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `char`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `str`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `slice`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `slice_u8`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `const_ptr`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `mut_ptr`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `i8`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `i16`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `i32`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `i64`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `i128`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `isize`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `u8`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `u16`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `u32`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `u64`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `u128`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `usize`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `f32`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `f64`.
 |
 error: duplicate lang item in crate `core`: `bool`.
 = note: first defined in crate `core`.
 |

 error: duplicate lang item in crate `core`: `sized`.
 = note: first defined in crate `core`.

 |
 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `char`.

 |
 error: duplicate lang item in crate `core`: `unsize`.
 = note: first defined in crate `core`.
 |

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `str`.
 |
 error: duplicate lang item in crate `core`: `copy`.
 |
 = note: first defined in crate `core`.

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `slice`.
 |
 error: duplicate lang item in crate `core`: `clone`.
 = note: first defined in crate `core`.
 |

 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `slice_u8`.

 |
 error: duplicate lang item in crate `core`: `sync`.
 = note: first defined in crate `core`.
 |

 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `const_ptr`.

 |
 error: duplicate lang item in crate `core`: `freeze`.
 = note: first defined in crate `core`.
 |

 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `mut_ptr`.

 |
 error: duplicate lang item in crate `core`: `drop`.
 = note: first defined in crate `core`.
 |

 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `i8`.

 |
 error: duplicate lang item in crate `core`: `coerce_unsized`.
 = note: first defined in crate `core`.

 |
 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `i16`.

 |
 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `dispatch_from_dyn`.

 |
 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `i32`.

 |
 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `add`.

 |
 error: duplicate lang item in crate `core`: `i64`.
 = note: first defined in crate `core`.

 |
 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `sub`.

 |
 error: duplicate lang item in crate `core`: `i128`.
 = note: first defined in crate `core`.

 |
 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `mul`.

 |
 error: duplicate lang item in crate `core`: `isize`.
 = note: first defined in crate `core`.
 |

 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `div`.

 |
 error: duplicate lang item in crate `core`: `u8`.
 = note: first defined in crate `core`.
 |

 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `rem`.

 |
 error: duplicate lang item in crate `core`: `u16`.
 = note: first defined in crate `core`.
 |

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `neg`.
 |
 error: duplicate lang item in crate `core`: `u32`.
 = note: first defined in crate `core`.
 |

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `not`.
 |
 error: duplicate lang item in crate `core`: `u64`.
 |
 = note: first defined in crate `core`.

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `bitxor`.
 |
 error: duplicate lang item in crate `core`: `u128`.
 |
 = note: first defined in crate `core`.

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `bitand`.
 |
 error: duplicate lang item in crate `core`: `usize`.
 |
 = note: first defined in crate `core`.

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `bitor`.
 error: duplicate lang item in crate `core`: `f32`.
 |
 |
 = note: first defined in crate `core`.

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `shl`.
 error: duplicate lang item in crate `core`: `f64`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `shr`.
 error: duplicate lang item in crate `core`: `sized`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `add_assign`.
 error: duplicate lang item in crate `core`: `unsize`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `sub_assign`.
 error: duplicate lang item in crate `core`: `copy`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `mul_assign`.
 error: duplicate lang item in crate `core`: `clone`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `div_assign`.
 error: duplicate lang item in crate `core`: `sync`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `rem_assign`.
 error: duplicate lang item in crate `core`: `freeze`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `bitxor_assign`.
 error: duplicate lang item in crate `core`: `drop`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `bitand_assign`.
 error: duplicate lang item in crate `core`: `coerce_unsized`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `bitor_assign`.
 error: duplicate lang item in crate `core`: `dispatch_from_dyn`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `shl_assign`.
 error: duplicate lang item in crate `core`: `add`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `sub`.
 error: duplicate lang item in crate `core`: `shr_assign`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `index`.
 error: duplicate lang item in crate `core`: `mul`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `index_mut`.
 error: duplicate lang item in crate `core`: `div`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `rem`.
 error: duplicate lang item in crate `core`: `unsafe_cell`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `neg`.
 |
 error: duplicate lang item in crate `core`: `va_list`.
 = note: first defined in crate `core`.

 |
 error: duplicate lang item in crate `core`: `not`.
 = note: first defined in crate `core`.
 |
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `bitxor`.
 |
 error: duplicate lang item in crate `core`: `deref`.
 = note: first defined in crate `core`.
 |

 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `bitand`.

 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `deref_mut`.
 error: duplicate lang item in crate `core`: `bitor`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `receiver`.
 error: duplicate lang item in crate `core`: `shl`.
 |
 |
 = note: first defined in crate `core`.

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `fn`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `fn_mut`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `fn_once`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `future_trait`.
 error: duplicate lang item in crate `core`: `shr`.
 |
 = note: first defined in crate `core`.

 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `add_assign`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `sub_assign`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `mul_assign`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `div_assign`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `rem_assign`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `bitxor_assign`.
 error: duplicate lang item in crate `core`: `generator_state`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `bitand_assign`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `bitor_assign`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `shl_assign`.
 |
 = note: first defined in crate `core`.

 |
 error: duplicate lang item in crate `core`: `shr_assign`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `index`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `index_mut`.
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `unsafe_cell`.
 |

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `generator`.
 error: duplicate lang item in crate `core`: `va_list`.
 |
 |
 = note: first defined in crate `core`.

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `deref`.
 |
 error: duplicate lang item in crate `core`: `unpin`.
 = note: first defined in crate `core`.

 |
 error: duplicate lang item in crate `core`: `deref_mut`.
 = note: first defined in crate `core`.
 |

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `receiver`.
 error: duplicate lang item in crate `core`: `pin`.
 |
 = note: first defined in crate `core`.
 |

 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `fn`.
 |

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `eq`.
 error: duplicate lang item in crate `core`: `fn_mut`.
 |
 |
 = note: first defined in crate `core`.

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `fn_once`.
 |
 error: duplicate lang item in crate `core`: `partial_ord`.
 = note: first defined in crate `core`.

 |
 error: duplicate lang item in crate `core`: `future_trait`.
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `generator_state`.
 |
 error: duplicate lang item in crate `core`: `ord`.
 |
 = note: first defined in crate `core`.

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `generator`.
 |
 error: duplicate lang item in crate `core`: `panic`.
 = note: first defined in crate `core`.
 |

 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `unpin`.

 |
 error: duplicate lang item in crate `core`: `panic_bounds_check`.
 = note: first defined in crate `core`.
 |

 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `pin`.

 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `eq`.
 error: duplicate lang item in crate `core`: `panic_info`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `partial_ord`.
 error: duplicate lang item in crate `core`: `drop_in_place`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `ord`.
 error: duplicate lang item in crate `core`: `alloc_layout`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `panic`.
 error: duplicate lang item in crate `core`: `phantom_data`.
 |
 |
 = note: first defined in crate `core`.

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `panic_bounds_check`.
 error: duplicate lang item in crate `core`: `manually_drop`.
 |
 |
 = note: first defined in crate `core`.
 = note: first defined in crate `core`.


 error: duplicate lang item in crate `core`: `panic_info`.
 error: duplicate lang item in crate `core`: `maybe_uninit`.
 |
 |
 = note: first defined in crate `core`.

 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `drop_in_place`.
 |
 error: duplicate lang item in crate `core`: `align_offset`.
 = note: first defined in crate `core`.
 |

 = note: first defined in crate `core`.
 error: duplicate lang item in crate `core`: `alloc_layout`.

 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `phantom_data`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `manually_drop`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `maybe_uninit`.
 |
 = note: first defined in crate `core`.

 error: duplicate lang item in crate `core`: `align_offset`.
 |
 = note: first defined in crate `core`.

 error: aborting due to 79 previous errors

 error: argument should be `&PanicInfo`
 --> src/lib.rs:6:17
 |
 6 | fn panic(_info: &core::panic::PanicInfo) -> ! {
 |                 ^^^^^^^^^^^^^^^^^^^^^^^

 error: Could not compile `playground`.
 warning: build failed, waiting for other jobs to finish...
 error: aborting due to 80 previous errors

 error: Could not compile `playground`.

 To learn more, run the command again with --verbose.

Remove the panic=abort line from the Cargo.toml
Rerun the command from step 2 (cargo test --target target.json -Z build-std=core --no-run). It works now.

My Guess

My guess is that the core library is somehow compiled twice when the panic=abort line is specified.

Version

cargo 1.39.0-nightly (fe0e5a48b 2019-09-04)

Contributor guide

Open the contributing guide

First steps

Read the whole issue, then the project's contributing guide.
Comment on the issue to say you are picking it up — it saves two people doing the same work.
Fork the repository and make your change on a branch.
Open a pull request that references the issue number.

Research direction

Reproduce the failure using the Cargo.toml and main.rs examples with cargo +nightly-2025-01-13 build -Zbuild-std and cargo test --target target.json -Z build-std=core --no-run. Trace Cargo's handling of panic = "abort", no-harness tests, and -Zbuild-std; done means these reproductions no longer emit duplicate core lang-item errors.

Written by the indexing model from the issue text.

Assessment

Tech stack: rust
Domain: build-system, tooling
Issue type: Bug
Difficulty: 4/5
Estimated time: 3-5 days
Activity status: Stale
Clarity: Mostly clear
Newbie friendliness: 35/100