RLS Crashing

[xogeny]

I'm currently running rustc 1.20.0-nightly (fc9ccfdbe 2017-06-25). I've run all of the following commands:

$ rustup install nightly
$ rustup default nightly
$ rustup component add rls
$ rustup component add rust-analysis
$ rustup component add rust-src

While running the vscode extension by @KalitaAlexey, I see RLS: Analysis Started followed by RLS: Analysis finished followed by RLS: Crashed.

In the output window I see:

thread '<unnamed>' panicked at 'could not run cargo: CargoError(Internal(Msg("failed to stat `/Users/mtiller/Source/my_proj/target/rls/debug/.fingerprint/rust-fmu-6371c09f679c0ce2/dep-bin-rust_fmu-6371c09f679c0ce2`")), State { next_error: Some(Error { repr: Os { code: 2, message: "No such file or directory" } }), backtrace: Some(stack backtrace:
   0:        0x10a26b2ae - backtrace::backtrace::trace::h50dae19105635900
   1:        0x10a26b44c - backtrace::capture::Backtrace::new::h29841072e5e6e49b
   2:        0x10a26a62d - error_chain::make_backtrace::hcffe27b0755719f7
   3:        0x10a1ad49e - cargo::ops::cargo_rustc::fingerprint::Fingerprint::update_local::ha46d83db51567a2d
   4:        0x10a1b5fd0 - _$LT$F$u20$as$u20$cargo..ops..cargo_rustc..job..FnBox$LT$A$C$$u20$R$GT$$GT$::call_box::h08ed6a3606a529e4
   5:        0x10a1b7345 - _$LT$F$u20$as$u20$cargo..ops..cargo_rustc..job..FnBox$LT$A$C$$u20$R$GT$$GT$::call_box::h9475d96ef80031bf
   6:        0x10a1c3c6e - cargo::ops::cargo_rustc::job_queue::JobQueue::run::_$u7b$$u7b$closure$u7d$$u7d$::h2d10942c5424dabd
   7:        0x10a089673 - _$LT$F$u20$as$u20$crossbeam..FnBox$GT$::call_box::hac838a5c59ecefc8
   8:        0x10a08bd9f - std::panicking::try::do_call::h683e73cdf03313f2
   9:        0x1102d5b5c - __rust_maybe_catch_panic
  10:        0x10a0cda8f - _$LT$F$u20$as$u20$alloc..boxed..FnBox$LT$A$GT$$GT$::call_box::h48add3badff46f6a
  11:        0x1102cf6fb - std::sys::imp::thread::Thread::new::thread_start::he5c82b73fbbeead1
  12:     0x7fffa7cfc93a - _pthread_body
  13:     0x7fffa7cfc886 - _pthread_start) })', src/libcore/result.rs:860
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
stack backtrace:
   0: std::sys::imp::backtrace::tracing::imp::unwind_backtrace
   1: std::panicking::default_hook::{{closure}}
   2: std::panicking::default_hook
   3: std::panicking::rust_panic_with_hook
   4: std::panicking::begin_panic
   5: std::panicking::begin_panic_fmt
   6: rust_begin_unwind
   7: core::panicking::panic_fmt
   8: core::result::unwrap_failed
Missing change, aborting. Found 2, expected Some(4)
[Error - 3:26:24 PM] Connection to server got closed. Server will not be restarted.

I've tried removing my target directory completely and rerunning vscode. I still get the same error. BTW, the error message is correct, the file /Users/mtiller/Source/my_proj/target/rls/debug/.fingerprint/rust-fmu-6371c09f679c0ce2/dep-bin-rust_fmu-6371c09f679c0ce2 does not exist. That seems to bring everything crashing down.

Frankly, given all the unique semantics of Rust, I find it nearly impossible to work with it without good IDE support. I simply don't (yet) use it regularly enough to keep all this stuff in my head. This is basically stopping me dead in my tracks. 😢

Any ideas?

[sophiajt]

The version in rustup right now is currently broken, waiting on the fix mentioned in #378 to land and make its way to rustup

[sophiajt]

According to @nrc, if you build the rls from source, you can avoid waiting until rustup gets the new version

[xogeny]

According to #378, the fix was put in master 2 days ago. So shouldn't the nightly already have it?

[sophiajt]

There's the manual step of syncing the repo rustup uses with the rls repo. I'm not sure if that step has happened yet (unfortunately both @nrc and myself just traveled half way across the world in the last day). Hopefully it'll go in soon.

[xogeny]

Is there a simple way to downgrade vs. build from source. I don't need bleeding edge. It is just that rls isn't in stable. Do we know at what point the nightly broke?

[sophiajt]

Here's the PR: rust-lang/rust#42911

Yes, you should be able to use the rls from a few days ago. Rustup can install other nightly versions. Eg. Instead of nightly install nightly-2017-06-23 or an earlier date (I can't remember the exact date it broke)

[sophiajt]

(You may also need to tweak the vscode plugin, I don't remember)

[Xanewok]

Change queue sometimes causing the Missing change, aborting. was commited 8 days ago (577ba2c), so anything before that might be a safe bet (I'm not sure which version of RLS rustup includes before that, though), but since it's alpha it may come with different problems of its own (like #330) 😛

[nrc]

As others have said, this is fixed on master and landing in nightly 'soon' (rust-lang/rust#42911)