Rust errors / Everything else
Rust compiler error · checked with rustc 1.99.0
Rust error E0668: #### Note: this error code is no longer emitted by the compiler
What it means#### Note: this error code is no longer emitted by the compiler.
Retired: rustc no longer emits this error code. You may still see it in old answers, books and CI logs from older toolchains; the explanation below is kept for reference.
The compiler team's explanation
Note: this error code is no longer emitted by the compiler.
Malformed inline assembly rejected by LLVM.
Erroneous code example:
#![feature(llvm_asm)]
fn main() {
let rax: u64;
unsafe {
llvm_asm!("" :"={rax"(rax));
println!("Accumulator is: {}", rax);
}
}LLVM checks the validity of the constraints and the assembly string passed to it. This error implies that LLVM seems something wrong with the inline assembly call.
In particular, it can happen if you forgot the closing bracket of a register constraint (see issue #51430), like in the previous code example.
From rustc --explain E0668 (1.99.0), part of the Rust project, MIT or Apache-2.0. Official page.
Related errors
- E0061this function takes N arguments but M were supplied
- E0412cannot find type in this scope
- E0515cannot return reference to local variable
- E0728await is only allowed inside async functions and blocks
- E0646`main` function is not allowed to have a `where` clause
- E0659`foo` is ambiguous
- E0670Rust 2015 does not permit the use of `async fn`
- E0695unlabeled `break` inside of a labeled block
Up next
Often hit nextE0061: this function takes N arguments but M were suppliedA related error from the same family.Read it next →Did this answer your question?