0.19.4 compilation error... on some project

[jice-nospam]

Hello,
This must be something really stupid on my side but I can't figure out what it is. I've been using rlua-0.19.4 without issues for months. Today I just created a new project to make some test and rlua fails to compile on stable-x86_64-pc-windows-msvc :

  Compiling rlua v0.19.4
error[E0308]: mismatched types
   --> x:\cargo\registry\src\github.com-1ecc6299db9ec823\rlua-0.19.4\src\function.rs:215:52
    |
215 |                 let dump_result = dump(state, Some(writer), bytes_ptr as *mut c_void, 0);
    |                                               ---- ^^^^^^ expected fn pointer, found fn item
    |                                               |
    |                                               arguments to this enum variant are incorrect
    |
    = note: expected fn pointer `unsafe extern "C" fn(_, *const std::ffi::c_void, _, *mut std::ffi::c_void) -> _`
                  found fn item `unsafe extern "C" fn(_, *const libc::c_void, _, *mut libc::c_void) -> _ {writer}`
    = note: when the arguments and return types match, functions can be coerced to function pointers
help: the type constructed contains `unsafe extern "C" fn(*mut lua_State, *const libc::c_void, usize, *mut libc::c_void) -> i32 {writer}` due to the type of the argument passed
   --> x:\cargo\registry\src\github.com-1ecc6299db9ec823\rlua-0.19.4\src\function.rs:215:47
    |
215 |                 let dump_result = dump(state, Some(writer), bytes_ptr as *mut c_void, 0);
    |                                               ^^^^^------^
    |                                                    |
    |                                                    this argument influences the type of `Some`
note: tuple variant defined here
   --> X:\rustup\toolchains\stable-x86_64-pc-windows-msvc\lib/rustlib/src/rust\library\core\src\option.rs:571:5
    |
571 |     Some(#[stable(feature = "rust1", since = "1.0.0")] T),
    |     ^^^^

My cargo.toml is really trivial and I can't find the difference between the project where it works and the one where it fails to compile...

[package]
name = "lua-test"
version = "0.1.0"
edition = "2021"

[dependencies]
rlua = "0.19.*"

[jugglerchris]

Looking at the error message, it looks like there's a disagreement about using std::ffi::c_void and libc::c_void for the writer's arguments. I'd have thought they'd be the same, but apparently not (if I'm reading it right) - maybe you've used one in the working project and the other in this one?

[jice-nospam]

Ok the issue might have been caused by a filesystem full that caused issues with cargo. My Cargo.lock had libc 0.2.33 when I had the error and now that I freed some space on the drive where cargo is downloading the dependencies, it works and the version is 0.2.144.