Texlab crashes sometimes when using it with nvim

[tmke8]

I see this in the lsp.log file:

[ERROR][2025-11-10 23:12:57] ...p/_transport.lua:36     "rpc"   "texlab"        "stderr"        "\nthread 'main' panicked at crates
/texlab/src/server.rs:396:77:\ncalled `Option::unwrap()` on a `None` value\nnote: run with `RUST_BACKTRACE=1` environment variable
to display a backtrace\n"

It seems to come from this line:

texlab/crates/texlab/src/server.rs

Line 396 in 28e9523

let range = document.line_index.offset_lsp_range(range).unwrap();

I don't really know what exactly triggers it. From my perspective it seems to happen randomly. If I can do something to debug this further, let me know.

[miEsMar]

FYI, just got the exact same crash.

[nolanking90]

@tmke8 could you post some of the surrounding lines in the lsp log. You might need to change the lsp log level in your neovim config depending on what you have it set to now.

vim.lsp.set_log_level("DEBUG") in your config

If you're comfortable rebuilding texlab locally, you could try changing that line to something like

                    let range = document
                        .line_index
                        .offset_lsp_range(range)
                        .unwrap_or_else(|| {
                            panic!(
                                "None returned from offset_lsp_range on {:?}; text: {}",
                                range, change.text
                            )
                        });

that hopefully would show you in the stack trace what block of tex it's referencing in the function call, and that might help you create a minimal example that can reproduce the bug.