thread '<unnamed>' panicked at 'called `Option::unwrap()` on a `None` value'

[Doaxan]

Version of VSCode: 1.10.1
OS: Fedora 25 x86_64

Description:
Sometimes rls dont work and i get:

thread '<unnamed>' panicked at 'called `Option::unwrap()` on a `None` value', /checkout/src/libcore/option.rs:323
note: Run with `RUST_BACKTRACE=1` for a backtrace.
thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"', /checkout/src/libcore/result.rs:860
thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"', /checkout/src/libcore/result.rs:860

editor-rs/vscode-rust#140 (comment)

[nrc]

Could you post the backtrace for the first panic please?

[Doaxan]

Sorry, I'm not really an expert. How can I do this? Run rls with RUST_BACKTRACE=1 and wait for panic?

[nrc]

Sorry, I'm not really an expert. How can I do this? Run rls with RUST_BACKTRACE=1 and wait for panic?

Yes. I assume you run visual studio from the command line, if not, you can. Then you just need to export RUST_BACKTRACE=1 before running code.

[Object905]

Also you can configure your vscode-rust like this:
"rust.rls": { "executable": "/home/obj/.cargo/bin/rustup", "args": [ "run", "nightly", "rls" ], "revealOutputChannelOn": "error", "env": { "RUST_LOG": "rls=debug", "RUST_BACKTRACE": "1" } }, To always run it with backtrace for further bug reports.

[oli-obk]

unfortunately, while this clears the "note: Run with RUST_BACKTRACE=1 for a backtrace." message, the backtrace doesn't show up in the output window. Probably some stderr vs stdout problem?

[FaultyRAM]

Also started getting this issue, though I can't say for sure when it started. I had to use RUST_BACKTRACE=full because rustc explicitly refused to provide a backtrace with RUST_BACKTRACE=1:

PS C:\Users\FaultyRAM> cargo install --git https://github.com/rust-lang-nursery/rls.git rls
    Updating git repository `https://github.com/rust-lang-nursery/rls.git`
  Installing rls v0.1.0 (https://github.com/rust-lang-nursery/rls.git#9fe3997f)
thread 'main' panicked at 'called `Option::unwrap()` on a `None` value', src\libcore\option.rs:323
stack backtrace:
   0:     0x7ff6d28cf4c5 - <unknown>
   1:     0x7ff6d28dd4c7 - <unknown>
   2:     0x7ff6d28dcda9 - <unknown>
   3:     0x7ff6d28dda21 - <unknown>
   4:     0x7ff6d28dd888 - <unknown>
   5:     0x7ff6d28dd7e1 - <unknown>
   6:     0x7ff6d28dd759 - <unknown>
   7:     0x7ff6d28e7a27 - <unknown>
   8:     0x7ff6d28e796c - <unknown>
   9:     0x7ff6d275ed38 - <unknown>
  10:     0x7ff6d26d6c1d - <unknown>
  11:     0x7ff6d270c762 - <unknown>
  12:     0x7ff6d271325e - <unknown>
  13:     0x7ff6d27134f8 - <unknown>
  14:     0x7ff6d2615ebc - <unknown>
  15:     0x7ff6d26199ff - <unknown>
  16:     0x7ff6d25bb054 - <unknown>
  17:     0x7ff6d26034f9 - <unknown>
  18:     0x7ff6d26062cb - <unknown>
  19:     0x7ff6d2600162 - <unknown>
  20:     0x7ff6d26e123c - <unknown>
  21:     0x7ff6d26deb73 - <unknown>
  22:     0x7ff6d262ce77 - <unknown>
  23:     0x7ff6d264115e - <unknown>
  24:     0x7ff6d24a2f73 - <unknown>
  25:     0x7ff6d248d2fb - <unknown>
  26:     0x7ff6d248325b - <unknown>
  27:     0x7ff6d248bb30 - <unknown>
  28:     0x7ff6d28dede1 - <unknown>
  29:     0x7ff6d28de028 - <unknown>
  30:     0x7ff6d29dfbe8 - git_revwalk_repository
  31:     0x7ff98b1e8363 - BaseThreadInitThunk

[FaultyRAM]

Actually this is probably not an RLS issue at all, I just got the same error trying to install rustfmt from Github. I'm on the latest nightly (e4eb964 2017-03-11) right now, I'll try reverting to the previous one (2017-03-04) and see if that changes anything.

[FaultyRAM]

Yep, looks like it's rust-lang/cargo#3819 which is being fixed in rust-lang/rust#40450. Sorry for the confusion!

[Xanewok]

I encountered a similar problem (cargo 0.19.0-nightly (4e95c6b41 2017-03-23)); I don't have any particular reproduction, just that I started editing stream of code fast (starting from idle, RLS Analysis: done):

thread '<unnamed>' panicked at 'called `Option::unwrap()` on a `None` value', /checkout/src/libcore/option.rs:329
stack backtrace:
   0:     0x7f0ebbb30f23 - std::sys::imp::backtrace::tracing::imp::unwind_backtrace::h0c49f46a3545f908
   1:     0x7f0ebbb2b654 - std::sys_common::backtrace::_print::hcef39a9816714c4c
   2:     0x7f0ebbb3efd7 - std::panicking::default_hook::{{closure}}::h7c3c94835e02f846
   3:     0x7f0ebbb3eb5b - std::panicking::default_hook::h0bf7bc3112fb107d
   4:     0x7f0ebbb3f4ab - std::panicking::rust_panic_with_hook::ha27630c950090fec
   5:     0x7f0ebbb3f384 - std::panicking::begin_panic::heb97fa3158b71158
   6:     0x7f0ebbb3f2b9 - std::panicking::begin_panic_fmt::h8144403278d84748
   7:     0x7f0ebbb3f247 - rust_begin_unwind
   8:     0x7f0ebbb7b4fd - core::panicking::panic_fmt::h3b0cca53e68f9654
   9:     0x7f0ebbb7b434 - core::panicking::panic::h4b991f5abe7d76d5
  10:     0x7f0ebda23e3c - <rls_vfs::File<U>>::make_change::h87bcf7c422816ea5
  11:     0x7f0ebdac9678 - rls::server::LsService::handle_message::{{closure}}::h07a834eb704da4e1
  12:     0x7f0ebda2b5cc - std::panicking::try::do_call::h74da05bea00149d3
  13:     0x7f0ebbb4839a - __rust_maybe_catch_panic
  14:     0x7f0ebda64af9 - <F as alloc::boxed::FnBox<A>>::call_box::h6ed0db43148802d9
  15:     0x7f0ebbb3dd54 - std::sys::imp::thread::Thread::new::thread_start::h75b208405df6dcf1
  16:     0x7f0ebb692063 - start_thread
  17:     0x7f0eba63862c - clone
  18:                0x0 - <unknown>

which was followed by subsequent PoisonErrors. I've been having those sporadically (not sure if that was always make_change, since I've run RLS with full backtrace only today) as well.

[sophiajt]

@Xanewok - Looks like your version of the nightly is out of date, so you may want to update it and try again.