Consumers of libjail-rs need to increase type_length_limit

[phyber]

Describe the bug
Rust 1.35.0 has broken some things via what is described in rust-lang/rust#58952, meaning libjail-rs no longer compiles.

To Reproduce
Attempt to compile under Rust 1.35.0

Expected behavior
The crate compiles.

Additional context
I’m not sure if there is anything for libjail to do here, but I thought a tracking issue might be good.

[fabianfreyer]

Thanks! Yes, I don't really know what to do here.

[fabianfreyer]

I guess we could increase the type_length_limit?

[fabianfreyer]

@phyber could you test whether #60 fixes the issue for you?

[fabianfreyer]

Reopening for @phyber's feedback, after merging of #60 automatically closed it.

[phyber]

So, it seems that increasing the type length limit in the library isn't enough and users of the library still have to take the same action.
This feels awful, I wonder if upstream will rollback their breakage.

I'm not able to play around with this too much at the moment either, I'm currently away and only have access to this stuff via a phone :)

[fabianfreyer]

Ugh. I'll release a version with the inclreased type_length_limit then, add a note to the changelog / release notes and readme, and keep this issue open as a tracking issue.

[fabianfreyer]

This may likely be related to one of:

• Have all methods of Filter and FilterMap use internal iteration rust-lang/rust#58730
• Exponential compile-time and type_length_limit blowup when nesting closure wrappers rust-lang/rust#54540

[phyber]

OK, now that I'm back home and can play with this properly on an actual computer, I've got this fix working.

Consumers of the library don't need to update their type_length_limit, testers of this fix do need to use the dev branch in their Cargo.toml ;)

[fabianfreyer]

Wonderful, will roll a release then :D

[fabianfreyer]

@phyber v0.1.0 is released with an updated type_length_limit.

[phyber]

This issue is back in Rust 1.38.0 and it's quite ridiculous now. I had to increase the type_length_limit to #![type_length_limit="314507289"] to get cargo test to run in libjail-rs. That's a pretty large increase.

[fabianfreyer]

ugh. Thanks for catching that :(

[fabianfreyer]

I can try to cut a release with the new type_length_limit... I wonder what the right thing to do is.

[phyber]

I tried to break down the large get_all iterator chain in the library into smaller chunks, but it didn't achieve anything. The compiler is unfortunately unhelpful here (there is an issue open, I don't have the number to hand), so we don't even know which part of the code it's complaining about to try and do things better :(