duplicate item in crate `core` #56

chaozju · 2020-06-12T05:02:36Z

I am testing with hello world case for build-std feature

my code

fn main() {
    println!("Hello, world!");
    println!("3 + 4 = {}",3+4);
}

then got

cargo +nightly build -Z build-std \
--release --target x86_64-unknown-linux-gnu
   Compiling compiler_builtins v0.1.25
   Compiling core v0.0.0 (/home/chao/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/libcore)
   Compiling cc v1.0.50
   Compiling libc v0.2.66
   Compiling autocfg v0.1.7
   Compiling std v0.0.0 (/home/chao/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/libstd)
   Compiling hashbrown v0.6.2
   Compiling backtrace-sys v0.1.32
   Compiling unwind v0.0.0 (/home/chao/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/libunwind)
   Compiling rustc-std-workspace-core v1.99.0 (/home/chao/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/tools/rustc-std-workspace-core)
   Compiling cfg-if v0.1.10
   Compiling alloc v0.0.0 (/home/chao/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/liballoc)
   Compiling rustc-demangle v0.1.16
   Compiling panic_abort v0.0.0 (/home/chao/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/libpanic_abort)
   Compiling backtrace v0.3.44
   Compiling rustc-std-workspace-alloc v1.99.0 (/home/chao/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/tools/rustc-std-workspace-alloc)
   Compiling panic_unwind v0.0.0 (/home/chao/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/libpanic_unwind)
   Compiling proc_macro v0.0.0 (/home/chao/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/libproc_macro)
   Compiling hello v0.1.0 (/home/chao/rust-playground/hello)
error: duplicate lang item in crate `core`: `bool`.
  |
  = note: the lang item is first defined in crate `core` (which `std` depends on)

error: duplicate lang item in crate `core`: `char`.
  |
  = note: the lang item is first defined in crate `core` (which `std` depends on)

error: duplicate lang item in crate `core`: `str`.
  |
  = note: the lang item is first defined in crate `core` (which `std` depends on)

error: duplicate lang item in crate `core`: `slice`.
  |
  = note: the lang item is first defined in crate `core` (which `std` depends on)

and

error[E0277]: the size for values of type `()` cannot be known at compilation time
 --> src/main.rs:3:27
  |
3 |     println!("3 + 4 = {}",3+4);
  |                           ^^^ doesn't have a size known at compile-time
  |
  = help: the trait `std::marker::Sized` is not implemented for `()`
  = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
  = note: required by `std::result::Result`
  = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the size for values of type `std::fmt::Error` cannot be known at compilation time
 --> src/main.rs:3:27
  |
3 |     println!("3 + 4 = {}",3+4);
  |                           ^^^ doesn't have a size known at compile-time
  |
  = help: the trait `std::marker::Sized` is not implemented for `std::fmt::Error`
  = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
  = note: required by `std::result::Result`
  = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the size for values of type `{integer}` cannot be known at compilation time
   --> src/main.rs:3:5
    |
3   |     println!("3 + 4 = {}",3+4);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    | 
   ::: /home/chao/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/libcore/fmt/mod.rs:281:20
    |
281 |     pub fn new<'b, T>(x: &'b T, f: fn(&T, &mut Formatter<'_>) -> Result) -> ArgumentV1<'b> {
    |                    - required by this bound in `std::fmt::ArgumentV1::<'a>::new`
    |
    = help: the trait `std::marker::Sized` is not implemented for `{integer}`
    = note: to learn more, visit <https://doc.rust-lang.org/book/ch19-04-advanced-types.html#dynamically-sized-types-and-the-sized-trait>
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 84 previous errors

For more information about this error, try `rustc --explain E0277`.
error: could not compile `hello`.

To learn more, run the command again with --verbose.
Makefile:18: recipe for target 'x86_64-gnu' failed
make: *** [x86_64-gnu] Error 101

The text was updated successfully, but these errors were encountered:

ehuss · 2020-06-13T18:40:49Z

Hm, I can't seem to reproduce. What version of nightly are you using?

chaozju · 2020-06-13T18:55:09Z

@ehuss
Hi, My toolchain info is

chao@DESKTOP-B79IRTG:~/rust-playground/hello$ rustup show
Default host: x86_64-unknown-linux-gnu
rustup home:  /home/chao/.rustup

installed toolchains
--------------------

stable-x86_64-unknown-linux-gnu (default)
nightly-x86_64-unknown-linux-gnu
1.40.0-x86_64-unknown-linux-gnu

installed targets for active toolchain
--------------------------------------

riscv64gc-unknown-linux-gnu
riscv64gc-unknown-none-elf
wasm32-wasi
x86_64-unknown-linux-gnu
x86_64-unknown-linux-musl

active toolchain
----------------

stable-x86_64-unknown-linux-gnu (default)
rustc 1.42.0 (b8cedc004 2020-03-09)

ehuss · 2020-06-13T19:04:45Z

That doesn't show the nightly version you are using. rustc +nightly -V shows which nightly version you have.

chaozju · 2020-06-13T19:20:36Z

@ehuss

OOPS

chao@DESKTOP-B79IRTG:~/rust-playground/hello$ rustc +nightly -V
rustc 1.44.0-nightly (f509b26a7 2020-03-18)

ehuss · 2020-06-13T20:24:57Z

2020-03-18 This is quite old. Can you try with the latest nightly? rustup update nightly can be used to update.

chaozju · 2020-06-14T01:41:18Z

@ehuss
same error after updating nightly

ehuss · 2020-06-14T14:14:45Z

Which exact version did you use?

chaozju · 2020-06-14T15:34:49Z

@ehuss
rustc 1.46.0-nightly (feb3536eb 2020-06-09)

dbdr · 2020-07-07T07:38:39Z

I'm getting the same error with 1.46.0-nightly (0c03aee8b 2020-07-05) and panic="abort" in Cargo.toml. Changing panic to "unwind" removes the error.

@chaozju, did you use panic="abort"?

panic="abort" also works when using -Z build-std=panic_abort,std, as suggested by @alexcrichton in #29.

chaozju · 2020-07-08T05:08:02Z

@dbdr It works, THX

gmorer · 2021-02-15T17:10:21Z

Hi, I got the same error with rustc 1.51.0-nightly (04caa632d 2021-01-30) and adding a dependencie:

Cargo.toml:

[package]
name = "rust_issue"
version = "0.1.0"
authors = ["gmorer"]
edition = "2018"

[lib]
crate-type = ["lib"]

[profile.dev]
panic = "abort"

[profile.release]
panic = "abort"

[dependencies]
wasm-bindgen = "0.2"

src/lib.rs:

#![no_std]

extern crate alloc;
use alloc::boxed::Box;

pub fn my_fn() -> i32 {
    let mem = Box::new(4);
    *mem
}

compile line:

cargo build --target=wasm32-unknown-unknown  -Z build-std=alloc,panic_abort

Got the following error:

$> cargo build --target=wasm32-unknown-unknown  -Z build-std=alloc,panic_abort
   Compiling core v0.0.0 (/home/me/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core)
  [...]
   Compiling panic_abort v0.0.0 (/home/me/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/panic_abort)
   Compiling rust_issue v0.1.0 (/home/me/gits/rust_issue)
error: duplicate lang item in crate `core` (which `alloc` depends on): `bool`.
  |
  = note: the lang item is first defined in crate `core` (which `rust_issue` depends on)
  = note: first definition in `core` loaded from /home/me/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/wasm32-unknown-unknown/lib/libcore-73412d1456c20040.rlib
  = note: second definition in `core` loaded from /home/me/gits/rust_issue/target/wasm32-unknown-unknown/debug/deps/libcore-d3db196937483bcf.rmeta

error: duplicate lang item in crate `core` (which `alloc` depends on): `char`.
  |
  = note: the lang item is first defined in crate `core` (which `rust_issue` depends on)
  = note: first definition in `core` loaded from /home/me/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/wasm32-unknown-unknown/lib/libcore-73412d1456c20040.rlib
  = note: second definition in `core` loaded from /home/me/gits/rust_issue/target/wasm32-unknown-unknown/debug/deps/libcore-d3db196937483bcf.rmeta

error: duplicate lang item in crate `core` (which `alloc` depends on): `str`.
  |
  = note: the lang item is first defined in crate `core` (which `rust_issue` depends on)
  = note: first definition in `core` loaded from /home/me/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/wasm32-unknown-unknown/lib/libcore-73412d1456c20040.rlib
  = note: second definition in `core` loaded from /home/me/gits/rust_issue/target/wasm32-unknown-unknown/debug/deps/libcore-d3db196937483bcf.rmeta

ehuss · 2021-03-08T21:50:40Z

@gmorer you have to ensure your dependencies do not use std if you are not building std. wasm-bindgen has a default std feature, so it has to be turned off:

wasm-bindgen = {version="0.2", default-features=false}

However, it looks like wasm-bindgen is broken in no_std environments. This line assumes mem:: is available, but it is gated here.

Tested with: CARGO_PROFILE_DEV_PANIC=unwind \ cargo test -Zbuild-std=std --target x86_64-unknown-linux-gnu (Changing panic to unwind avoids rust-lang/wg-cargo-std-aware#56)

ehuss · 2023-05-03T23:22:33Z

I'm going to close as it isn't clear that there is an issue here. Better panic support is tracked in #29, and it looks like the wasm_bindgen issue was an issue with an external package.

tbu- · 2025-03-25T10:21:45Z

I had a similar problem and passing -Z build-std=panic_abort,std helped.

crumblingstatue mentioned this issue May 3, 2021

Source file names are included into a release binary even if abort upon panic is enabled rust-lang/rust#75263

Closed

ehuss mentioned this issue Jul 9, 2021

"duplicate lang item in crate core" when building #71

Closed

nicholasbishop mentioned this issue Aug 7, 2021

Fix docstring tests and test them in the CI rust-osdev/uefi-rs#267

Merged

This was referenced Dec 15, 2021

rust-lld: error: --shared-memory is disallowed Amanieu/parking_lot#308

Closed

Duplicate use of std core when using -Z build-std rust-lang/cargo#10200

Closed

ehuss closed this as not planned Won't fix, can't repro, duplicate, stale May 3, 2023

klensy mentioned this issue Sep 20, 2023

Build std with panic = "abort" errors with a bunch of duplicated lang items rust-lang/cargo#15347

Closed

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duplicate item in crate `core` #56

duplicate item in crate `core` #56

chaozju commented Jun 12, 2020

ehuss commented Jun 13, 2020

chaozju commented Jun 13, 2020

ehuss commented Jun 13, 2020

chaozju commented Jun 13, 2020 •

edited

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ehuss commented Jun 13, 2020

chaozju commented Jun 14, 2020

ehuss commented Jun 14, 2020

chaozju commented Jun 14, 2020

dbdr commented Jul 7, 2020

chaozju commented Jul 8, 2020

gmorer commented Feb 15, 2021

ehuss commented Mar 8, 2021

ehuss commented May 3, 2023

tbu- commented Mar 25, 2025

duplicate item in crate core #56

duplicate item in crate core #56

Comments

chaozju commented Jun 12, 2020

ehuss commented Jun 13, 2020

chaozju commented Jun 13, 2020

ehuss commented Jun 13, 2020

chaozju commented Jun 13, 2020 • edited Loading

ehuss commented Jun 13, 2020

chaozju commented Jun 14, 2020

ehuss commented Jun 14, 2020

chaozju commented Jun 14, 2020

dbdr commented Jul 7, 2020

chaozju commented Jul 8, 2020

gmorer commented Feb 15, 2021

ehuss commented Mar 8, 2021

ehuss commented May 3, 2023

tbu- commented Mar 25, 2025

duplicate item in crate `core` #56

duplicate item in crate `core` #56

chaozju commented Jun 13, 2020 •

edited

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