fuzz/ failing to build

[howardjohn]

Step #3 - "compile-libfuzzer-address-x86_64": �[0m�[1m�[38;5;9merror[E0635]�[0m�[0m�[1m: unknown feature `stdsimd`�[0m
Step #3 - "compile-libfuzzer-address-x86_64": �[0m  �[0m�[0m�[1m�[38;5;12m--> �[0m�[0m/rust/registry/src/index.crates.io-6f17d22bba15001f/ahash-0.8.6/src/lib.rs:99:42�[0m
Step #3 - "compile-libfuzzer-address-x86_64": �[0m   �[0m�[0m�[1m�[38;5;12m|�[0m
Step #3 - "compile-libfuzzer-address-x86_64": �[0m�[1m�[38;5;12m99�[0m�[0m �[0m�[0m�[1m�[38;5;12m|�[0m�[0m �[0m�[0m#![cfg_attr(feature = "stdsimd", feature(stdsimd))]�[0m
Step #3 - "compile-libfuzzer-address-x86_64": �[0m   �[0m�[0m�[1m�[38;5;12m| �[0m�[0m                                         �[0m�[0m�[1m�[38;5;9m^^^^^^^�[0m
Step #3 - "compile-libfuzzer-address-x86_64": 
Step #3 - "compile-libfuzzer-address-x86_64": �[1m�[32m   Compiling�[0m linux-raw-sys v0.3.8
Step #3 - "compile-libfuzzer-address-x86_64": �[1m�[32m   Compiling�[0m prettyplease v0.1.25
Step #3 - "compile-libfuzzer-address-x86_64": �[1m�[32m   Compiling�[0m syn v2.0.39
Step #3 - "compile-libfuzzer-address-x86_64": �[0m�[1mFor more information about this error, try `rustc --explain E0635`.�[0m
Step #3 - "compile-libfuzzer-address-x86_64": �[1m�[31merror�[0m�[1m:�[0m could not compile `ahash` (lib) due to 1 previous error

sorry I cannot share the full link, the fuzz CI is private.

Maybe we should also make presubmit do a cargo check against fuzz/ as well?

[ilrudie]

We need some public way to expose that PR X is going to prevent private CI from functioning.

Can you provide a commit that's broken if folks want to experiment with different ways to detect broken fuzz dependencies?

[howardjohn]

Just the execution of the fuzzer is private, you can run cargo check under fuzz/ and it should fail

[howardjohn]

Hmm actually it doesn't 🤔 maybe they have some weird environment. Will look into it

[ilrudie]

Sounds good. I was running cargo check and cargo build fuzz/ and couldn't get a failure. I figured someone must have already fixed that issue which is why I asked for the broken commit...

[howardjohn]

cargo +nightly fuzz build --release --debug-assertions can reproduce it. Or just cargo +nightly check, so it must be "does not build on nightly"

[howardjohn]

Unintentionally fixed in #805, so lets just do that