Slow compile times due to compiler issue

[kettle11]

This isn't directly actionable by glow, but I wanted to open an issue to draw attention to it.

I was surprised at how long glow took to compile given its complexity (~14 seconds on my machine).

I asked about it in the Rust compiler team Zulip and they diagnosed it as this issue: rust-lang/rust#65510 (Quadratic slowdown for lookup of bounds on associated types)

@matthewjasper believes this should be fixed by rust-lang/rust#73905

[kettle11]

So rust-lang/rust#73905 was merged and I decided to see how it impacts glow compile times.

Clean build times of glow on stable: ~15.3 seconds
Clean build times of glow on nightly: ~3.6 seconds

This is a fantastic improvement! :)

Thanks @matthewjasper!