LTO does not work due to default rlib target, causing extremely large static build artifacts

[Humandoodlebug]

In order to fix #138, CrateType::Lib is always selected when building (see here). Unfortunately, this means LTO configuration is ignored (see this cargo issue), meaning our gstreamer plugins are ridiculously large, especially for static builds (hundreds of megabytes when they should be less than ten).

Reverting 596c582 does fix it, however this would probably break #138.

[sdroege]

Thanks for finding this. I've added that also to the GStreamer Rust tracker issue.

Would it be possible to only build the rlib when the test target is selected? cargo-c should know that, right?

[lu-zero]

Yes and yes, thank you for debugging it :)

[sdroege]

@Humandoodlebug When statically linking multiple LTO'd GStreamer Rust plugins, are you not running into rust-lang/rust#44322 (comment) ?

[lu-zero]

One annoyance is that it might again require rebuilding everything twice.

[lu-zero]

The upstream open issue is rust-lang/cargo#4611

[Humandoodlebug]

Thank you for fixing this so quickly :)
@sdroege we haven't hit that yet, but we almost certainly will soon - thanks for the heads up.