LspServer panicked at 'index out of bounds: the len is 0 but the index is 0'

[ralpha]

Just opened a project in VSCode and it showed a message "The Rust Analyzer Language Server server crashed 5 times in the last 3 minutes. The server will not be restarted.".

Here is the output:

thread 'LspServer' panicked at 'index out of bounds: the len is 0 but the index is 0', crates/rust-analyzer/src/reload.rs:358:41
stack backtrace:
   0: rust_begin_unwind
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/panicking.rs:142:14
   2: core::panicking::panic_bounds_check
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/panicking.rs:84:5
   3: rust_analyzer::reload::<impl rust_analyzer::global_state::GlobalState>::switch_workspaces
   4: rust_analyzer::main_loop::<impl rust_analyzer::global_state::GlobalState>::handle_event
   5: rust_analyzer::main_loop::<impl rust_analyzer::global_state::GlobalState>::run
   6: rust_analyzer::main_loop::main_loop
   7: rust_analyzer::run_server
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: "SendError(..)"', lib/lsp-server/src/stdio.rs:29:37
stack backtrace:
   0: rust_begin_unwind
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/panicking.rs:142:14
   2: core::result::unwrap_failed
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/result.rs:1785:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
[Info  - 1:58:21 PM] Connection to server got closed. Server will restart.
[Error - 1:58:21 PM] Request textDocument/foldingRange failed.
Error: Connection got disposed.
	at Object.dispose (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:29:4495)
	at Object.dispose (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:34:10387)
	at _l.handleConnectionClosed (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:36:10613)
	at _l.handleConnectionClosed (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:39:49379)
	at t (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:36:10321)
	at Pa.invoke (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:14370)
	at Br.fire (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:15139)
	at Nt (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:3:6314)
	at Pa.invoke (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:14370)
	at Br.fire (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:15139)
	at xo.fireClose (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:17394)
	at Socket.<anonymous> (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:18924)
	at Socket.emit (node:events:402:35)
	at Pipe.<anonymous> (node:net:687:12)
[Error - 1:58:21 PM] Request textDocument/hover failed.
Error: Connection got disposed.
	at Object.dispose (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:29:4495)
	at Object.dispose (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:34:10387)
	at _l.handleConnectionClosed (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:36:10613)
	at _l.handleConnectionClosed (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:39:49379)
	at t (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:36:10321)
	at Pa.invoke (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:14370)
	at Br.fire (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:15139)
	at Nt (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:3:6314)
	at Pa.invoke (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:14370)
	at Br.fire (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:15139)
	at xo.fireClose (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:17394)
	at Socket.<anonymous> (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:18924)
	at Socket.emit (node:events:402:35)
	at Pipe.<anonymous> (node:net:687:12)
[Error - 1:58:21 PM] Request textDocument/codeLens failed.
Error: Connection got disposed.
	at Object.dispose (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:29:4495)
	at Object.dispose (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:34:10387)
	at _l.handleConnectionClosed (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:36:10613)
	at _l.handleConnectionClosed (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:39:49379)
	at t (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:36:10321)
	at Pa.invoke (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:14370)
	at Br.fire (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:15139)
	at Nt (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:3:6314)
	at Pa.invoke (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:14370)
	at Br.fire (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:15139)
	at xo.fireClose (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:17394)
	at Socket.<anonymous> (/home/user/.vscode/extensions/rust-lang.rust-analyzer-0.4.1141-linux-x64/out/main.js:2:18924)
	at Socket.emit (node:events:402:35)
	at Pipe.<anonymous> (node:net:687:12)
thread 'LspServer' panicked at 'index out of bounds: the len is 0 but the index is 0', crates/rust-analyzer/src/reload.rs:358:41
stack backtrace:
   0: rust_begin_unwind
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/panicking.rs:142:14
   2: core::panicking::panic_bounds_check
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/panicking.rs:84:5
   3: rust_analyzer::reload::<impl rust_analyzer::global_state::GlobalState>::switch_workspaces
   4: rust_analyzer::main_loop::<impl rust_analyzer::global_state::GlobalState>::handle_event
   5: rust_analyzer::main_loop::<impl rust_analyzer::global_state::GlobalState>::run
   6: rust_analyzer::main_loop::main_loop
   7: rust_analyzer::run_server
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: "SendError(..)"', lib/lsp-server/src/stdio.rs:29:37
stack backtrace:
   0: rust_begin_unwind
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/panicking.rs:142:14
   2: core::result::unwrap_failed
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/result.rs:1785:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
[Info  - 1:58:22 PM] Connection to server got closed. Server will restart.
thread 'LspServer' panicked at 'index out of bounds: the len is 0 but the index is 0', crates/rust-analyzer/src/reload.rs:358:41
stack backtrace:
   0: rust_begin_unwind
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/panicking.rs:142:14
   2: core::panicking::panic_bounds_check
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/panicking.rs:84:5
   3: rust_analyzer::reload::<impl rust_analyzer::global_state::GlobalState>::switch_workspaces
   4: rust_analyzer::main_loop::<impl rust_analyzer::global_state::GlobalState>::handle_event
   5: rust_analyzer::main_loop::<impl rust_analyzer::global_state::GlobalState>::run
   6: rust_analyzer::main_loop::main_loop
   7: rust_analyzer::run_server
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: "SendError(..)"', lib/lsp-server/src/stdio.rs:29:37
stack backtrace:
   0: rust_begin_unwind
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/panicking.rs:142:14
   2: core::result::unwrap_failed
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/result.rs:1785:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
[Info  - 1:58:23 PM] Connection to server got closed. Server will restart.
thread 'LspServer' panicked at 'index out of bounds: the len is 0 but the index is 0', crates/rust-analyzer/src/reload.rs:358:41
stack backtrace:
   0: rust_begin_unwind
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/panicking.rs:142:14
   2: core::panicking::panic_bounds_check
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/panicking.rs:84:5
   3: rust_analyzer::reload::<impl rust_analyzer::global_state::GlobalState>::switch_workspaces
   4: rust_analyzer::main_loop::<impl rust_analyzer::global_state::GlobalState>::handle_event
   5: rust_analyzer::main_loop::<impl rust_analyzer::global_state::GlobalState>::run
   6: rust_analyzer::main_loop::main_loop
   7: rust_analyzer::run_server
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: "SendError(..)"', lib/lsp-server/src/stdio.rs:29:37
stack backtrace:
   0: rust_begin_unwind
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/panicking.rs:142:14
   2: core::result::unwrap_failed
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/result.rs:1785:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
[Info  - 1:58:24 PM] Connection to server got closed. Server will restart.
thread 'LspServer' panicked at 'index out of bounds: the len is 0 but the index is 0', crates/rust-analyzer/src/reload.rs:358:41
stack backtrace:
   0: rust_begin_unwind
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/panicking.rs:142:14
   2: core::panicking::panic_bounds_check
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/panicking.rs:84:5
   3: rust_analyzer::reload::<impl rust_analyzer::global_state::GlobalState>::switch_workspaces
   4: rust_analyzer::main_loop::<impl rust_analyzer::global_state::GlobalState>::handle_event
   5: rust_analyzer::main_loop::<impl rust_analyzer::global_state::GlobalState>::run
   6: rust_analyzer::main_loop::main_loop
   7: rust_analyzer::run_server
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: "SendError(..)"', lib/lsp-server/src/stdio.rs:29:37
stack backtrace:
   0: rust_begin_unwind
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/std/src/panicking.rs:584:5
   1: core::panicking::panic_fmt
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/panicking.rs:142:14
   2: core::result::unwrap_failed
             at /rustc/e092d0b6b43f2de967af0887873151bb1c0b18d3/library/core/src/result.rs:1785:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
[Error - 1:58:25 PM] The Rust Analyzer Language Server server crashed 5 times in the last 3 minutes. The server will not be restarted. See the output for more information.

Issue started since today. (was working fine 20 hours ago)
When I reload the same errors come up.
Opening a different project it gives the same result. (crashed with same error)
I switched to release version for now to fix the issue.

I hope this helps with debugging the issue.

rust-analyzer version: rust-analyzer version: 0.4.1141-standalone (0b1ed70 2022-07-25) (Pre-release)

rustc version: rustc 1.61.0 (fe5b13d68 2022-05-18)

relevant settings: NA

[ralpha]

Here are the related line for the errors:

https://github.com/rust-lang/rust-analyzer/blame/0b1ed70c121e1fefa9d32b87091fbac16a37c215/crates/rust-analyzer/src/reload.rs#L358

https://github.com/rust-lang/rust-analyzer/blame/0b1ed70c121e1fefa9d32b87091fbac16a37c215/lib/lsp-server/src/stdio.rs#L29

Looks like problem might have been introduced in this commit: aeb0774

[Veykril]

Ye that was an oversight on my part, if proc-macros are disabled we just panic

[ralpha]

Ye that was an oversight on my part, if proc-macros are disabled we just panic

Yeah that can be it, still have proc macros disabled because of a previous issue, from quite some time ago. Have never re-enabled it.
But at least we found a bug that way :)