Disabling optimizations for specific packages in Cargo.toml?

[adundovi]

Describe the bug
I've encountered the following bug in Rust, i.e., when building a package with perseus build (or serve or test), the "Building your app to Wasm..." step never ends (finally being killed by the OOM killer). It only happens for the --release target of wasm32, not for x86_64 and wasm32 without --release.

A workaround for this bug is to disable optimizations for fluent-bundle.

How do I specify opt-level = 0 for the fluent-bundle package in Cargo.toml so that perseus-cli picks it up and builds the package with the option present? I tried just putting in Cargo.toml, but it didn't work. It would be great to see in Perseus' docs how to do this...

Environment:

• Perseus Version: 0.3.0-beta.17
• Sycamore Version: 0.6
• OS: Linux

[adundovi]

Adding

[profile.release.package]
fluent-bundle = { opt-level = 2 }

in .perseus/Cargo.toml works as the mentioned workaround, but I wouldn't like to modify the .perseus directory manually.

[phaleth]

As far as optimizations are concerned I'd think the --release flag is one of the gotchas.

I suggest dropping the --release flag completely as hinted here #52 (comment).

In case you want to avoid modifying .perseus/ dir contents you can use the perseus-size-opt plugin as demonstrated here #69 (comment).

Also, please, next time specify at least your linux distro.

[adundovi]

Hmm, to me it looks like the --release flag is always on, whether I pass --release to build/serve/export or not.

[arctic-hen7]

@adundovi I think this should probably be an issue on the size optimizations plugin, as Perseus itself is agnostic about how you perform optimizations. I could also create another plugin, but I think the simplest thing is just to patch the size optimizations plugin to perform that workaround.

[adundovi]

@arctic-hen7 thanks for the feedback. Are the perseus plugins listed somewhere?

[arctic-hen7]

Yes! See the Plugins section on the website. (At the moment there's only one...)

[arctic-hen7]

Okay, the size optimizations plugin now has this patch inbuilt unless the default_2018() function is used (seeing as this only seems to affect Rust 2021). @adundovi I would recommend using v0.1.4 of that plugin to perform your size optimizations for you, and this error should then no longer be a problem! Please let me know if that's not the case and I'll reopen this issue.

[adundovi]

Hi @arctic-hen7, thank you for the plugin and for including the workaround in the plugin by default.

May I just note that I have to change the prescribed line on how to use the plugin into:

plugins: Plugins::new().plugin(|| perseus_size_opt(), SizeOpts::default())

since otherwise, I cannot compile:

plugins: Plugins::new().plugin(perseus_size_opt(), SizeOpts::default() )
                        expected an `Fn<()>` closure, found `Plugin<_, SizeOpts>`

[arctic-hen7]

Ah! Yes, sorry, that's an issue in the docs for the plugin. You don't need a closure, just use perseus_size_opt without the brackets. There's an example here.

[adundovi]

Eh, yes, you're right, and it makes perfect sense. (me embarrassed)

[adundovi]

Hmm, does not work after perseus clean.

[arctic-hen7]

Have you run perseus tinker afterward?

[adundovi]

No, I forgot. Afterward, it worked. Thank you.

[arctic-hen7]

No problem!