Update to rust master

[geomaster]

rust-lang/rust#19253 and rust-lang/rust@25f8051 have introduced changes
to the namespacing within the std::collections::hash_map, breaking some
of Cargo code which imported these.

rust-lang/rust@cf350ea, implementing changes proposed by RFC #344, have
also broken some code which relies on hash_set::SetItems (now renamed to
hash_set::Iter).

This PR fixes the incompatibilities: imports of
std::collections::hash_map::{Occupied, Vacant} have been replaced by
imports of std::collections::hash_map::Entry::{Occupied, Vacant} and one
instance where the SetItems has been used was replaced by the proper
usage of Iter.

[alexcrichton]

Cargo actually builds with a pinned version of the rust compiler, so you'll also have to update the date listed in src/rustversion.txt as well (you can see if travis failed/passed to see if it works). Thanks for this!

[geomaster]

@alexcrichton My rustc reports rustc 0.13.0-dev (2f3cff695 2014-12-22 17:11:37 +0000) for --version. Do I just write 2014-12-22 into src/rustversion.txt? Pardon my ignorance, this is the first time I'm contributing to a project on here so I'm kind of clueless :)

[alexcrichton]

Yep, that should do it!

[geomaster]

Okay, bumping the version triggered errors in Cargo's dependencies caused by the same breaking change. I fixed these locally, so I will submit pull requests to these libraries and we have to wait for them to be merged in order for this to build. Also, this triggers a compiler bug, further preventing the build in rustc that seems to be fixed by rust-lang/rust@c5aaa8c but is not yet in the 2014-12-22 nightly. So in any case we have to wait.

[alexcrichton]

If you add this to Cargo.toml locally you should be able to get past the compiler bug:

[profile.dev]
debug = false

I wouldn't commit that to this PR, but it should help out working locally!

[geomaster]

It seems that the issues in docopt/docopt.rs and servo/rust-url that prevented them from building on the latest rustc have been resolved. Fixing Cargo.toml seemed easy enough, but the registry library requires curl-rust, which in turn demands rust-url 0.2.0, and since rust-url doesn't have a release that accompanies the required commit (servo/rust-url@13be975), Cargo fetches 0.2.6 for curl-rust which is an older release that doesn't build on current rustc. Also the compiler bug still keeps Travis unhappy, not only here but on most other Rust projects that trigger it. What should I do now?

[alexcrichton]

Today's nightly has fixed the debuginfo ICE and I think a number of crates have all been updated, perhaps today's nightly could work?

[geomaster]

What does this mean?

failed to select a version for `url` (required by `cargo`):
all possible versions conflict with previously selected versions of `url`
version 0.2.6 in use by url v0.2.6
possible versions to select: [0.2.7]

On my machine it fetches the right version of that library but I bomb against an error in docopt.rs:

/home/geomaster/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/docopt-0.6.18/src/lib.rs:486:41: 486:54 error: attempt to bound type parameter with a nonexistent trait `StrAllocating`
/home/geomaster/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/docopt-0.6.18/src/lib.rs:486                where I: Iterator<S>, S: StrAllocating {

Fixing this (it was caused by rust-lang/rust@9b99436) I am greeted with:

/home/geomaster/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/docopt-0.6.18/src/parse.rs:385:30: 386:47 error: if and else have incompatible types: expected `fn(collections::vec::Vec<parse::Pattern>) -> parse::Pattern {parse::Optional}`, found `fn(collections::vec::Vec<parse::Pattern>) -> parse::Pattern {parse::Sequence}` (expected fn item, found a different fn item)
/home/geomaster/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/docopt-0.6.18/src/parse.rs:385                     let mk = if self.cur() == "]" { Optional }
/home/geomaster/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/docopt-0.6.18/src/parse.rs:386                              else { Sequence };
/home/geomaster/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/docopt-0.6.18/src/parse.rs:390:35: 390:38 error: mismatched types: expected `&u8`, found `collections::vec::Vec<parse::Pattern>` (expected &-ptr, found struct collections::vec::Vec)
/home/geomaster/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/docopt-0.6.18/src/parse.rs:390                             Ok(mk(seq))
                                                                                                                                 ^~~
/home/geomaster/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/docopt-0.6.18/src/parse.rs:390:29: 390:40 error: mismatched types: expected `core::result::Result<parse::Pattern, collections::string::String>`, found `core::result::Result<u8, _>` (expected enum parse::Pattern, found u8)
/home/geomaster/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/docopt-0.6.18/src/parse.rs:390                             Ok(mk(seq))
                                                                                                                           ^~~~~~~~~~~
<std macros>:5:9: 5:22 error: mismatched types: expected `&u8`, found `collections::vec::Vec<parse::Pattern>` (expected &-ptr, found struct collections::vec::Vec)
<std macros>:5         xs.into_vec()
                       ^~~~~~~~~~~~~
<std macros>:1:1: 8:2 note: in expansion of vec!
/home/geomaster/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/docopt-0.6.18/src/parse.rs:393:35: 393:58 note: expansion site
/home/geomaster/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/docopt-0.6.18/src/parse.rs:393:29: 393:59 error: mismatched types: expected `core::result::Result<parse::Pattern, collections::string::String>`, found `core::result::Result<u8, _>` (expected enum parse::Pattern, found u8)
/home/geomaster/.cargo/registry/src/gh.neting.cc-1ecc6299db9ec823/docopt-0.6.18/src/parse.rs:393                             Ok(mk(vec!(Alternates(alts))))

I'm not sure which change causes this, I'm not very fluent with Rust, so any help would be appreciated.

[geomaster]

I have updated the code so it now works with all the new breaking changes in Rust, with no deprecation warnings. However, some tests fail on the CI server. If you have any clue as to why this could have happened, assistance would be welcome.

[alexcrichton]

I'd prefer to keep this up here if possible (keep the logic duplication to a minimum). You should be able to keep it up here with something like:

let job = if compiled {
    Job::new as fn(Work, Work) -> Job
} else {
    Job::noop as fn(Work, Work) -> Job
};

[geomaster]

Thanks, will fix tomorrow, it's 6AM here now so kinda time to go to bed. What concerns me more are these two failed tests. I'm not sure if it's a regression caused by using a newer rustc or I screwed up something.

[alexcrichton]

It looks like these tests are failing because of a bug in rustdoc. Feel free to update the expected output to what rustdoc currently outputs, I'll just be sure to update it back once rustdoc is fixed!

And again, thanks so much for this!

[geomaster]

All done. The CI builds pass. You may want to perform some more review to ensure that I didn't do anything erroneous (I am again saying that the stuff in these commits is the first Rust code I've ever written so be extra careful), but oh well, it compiles fine, the tests pass, the changes were pretty much heavylifting with no much thought involved, so I guess it can be merged. The commits are a bit of a clusterfuck so some rebasing and renaming has to be done. If anything needs to be fixed still just let me know.

[alexcrichton]

Awesome work, thanks so much!

[geomaster]

Great! My first pull request ever - merged! :) Happy holidays @alexcrichton and everyone else, thank you for the wonderful work you did on Rust and related projects!