Crates using vulkano-shaders fail to build

[marc0246]

We have a bit of a situation in that all crates that use vulkano-shaders fail to build on docs.rs, at least as of 0.33, for reasons that are beyond me. There's no metadata for docs.rs in vulkano-shaders or any of these crates, and documenting of course works locally.

The following crates are affected:

• basalt
• egui_winit_vulkano
• ilmenite

[Nemo157]

It may have been rust-lang/rust#111461 giving a wrong error message, but not sure why it would have been erroring at all, I will queue a new build of those versions.

[Nemo157]

Hmmm, still failed with a more normal error message. I don't see why it's failing though, trying to do a local build using some of the options that docs.rs does doesn't cause any similar sort of failure, and there's no more useful data in the service logs. I can try and debug some more in a local docs.rs instance tomorrow.

[marc0246]

Thanks a lot! We really appreciate it. It had me stunned as well.

[Nemo157]

Mostly for future me debugging issues like this, what I eventually did was do the build manually inside the docs.rs build-environment

> docker run -it --rm ghcr.io/rust-lang/crates-build-env/linux-micro /bin/sh
# apt update
# apt install curl
# curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
# . ~/.cargo/env
# cargo install cargo-dl
# cargo dl ilmenite
# cd ilmenite-0.14.0
# cargo check
... errors about missing shaderc library, checked the build.rs and saw they detect docs.rs
# DOCS_RS=1 cargo check
... errors about proc-macro-error or proc-macro2 or something not supporting the latest stable compiler.....
# rustup default nightly
# DOCS_RS=1 cargo check
... expected failure
# ld target/debug/deps/libvulkano_shaders-ebee64e3e6bdf48d.so
ld: warning: cannot find entry symbol _start; not setting start address
ld: target/debug/deps/libvulkano_shaders-ebee64e3e6bdf48d.so: undefined reference to `shaderc_compile_options_initialize'
...

That gives a way to test locally too, DOCS_RS=1 cargo check fails in the same way outside the build environment. The issue is that when attempting to load the proc-macro's .so file it fails because of the missing shaderc library. It's probably worth opening an upstream issue about having rustc provide better diagnostics in this case, I can't find any existing issue about it.

[marc0246]

Alright, thank you for the help. I guess it's google/shaderc-rs#130 that broke things then.