Neovim LSP integration: Detach buffers only when attached

[larrybotha]

When switching to files that are not yet buffered I get the following error:

Buffer (id: [X]) is not attached to client (id: [Y]). Cannot detach.
"/path/to/file" 15L, 351B

This appears to be as a result of a race condition when detaching buffers - something in my config is potentially detaching buffers and then vectorcode attempts to do the same after they are already detached.

I tried to create a minimal neovim repro, but with the extent of my config it'd be a nightmare to minimise, so I've provided a screencast instead:

Recording.at.2025-12-16.22.53.40.Cropped.in.2025-12-16.22.54.37._compressed.webm

Reproduction Steps

• add a decade's worth of vim configs to neovim
• configure vectorcode lsp integration in neovim
• open an unbuffered file
• open a new unbuffered file in the same buffer

Expect: no error
Actual: error raised

Neovim Vectorcode Config

return {
"Davidyz/VectorCode",
version="*",
build="uv tool upgrade vectorcode",
dependencies= { "nvim-lua/plenary.nvim" },
cond=function()
returnvim.fn.executable("vectorcode") ==1end,
event= { "BufReadPost", "BufNewFile" },
config=function()
require("vectorcode").setup(
---@typeVectorCode.Opts
{
cli_cmds= {
vectorcode="vectorcode",
},
-- options used when attaching to LSP, below---@typeVectorCode.RegisterOptsasync_opts= {
debounce=100, -- Debounce time in milliseconds to avoid excessive updatesevents= { "BufWritePost", "InsertLeave", "BufReadPost" }, -- Events that trigger automatic file indexingexclude_this=true, -- Exclude current buffer from automatic indexingn_query=1, -- Number of queries to send for each indexing operationnotify=true, -- Show notifications when indexing operations occurquery_cb=require("vectorcode.utils").make_surrounding_lines_cb(-1), -- Use surrounding lines as context for better indexing-- Don't automatically index when files are manually registered-- Use `:VectorCode register` to register specific files for indexingrun_on_register=false,
},
async_backend="lsp", -- Backend to use for async operations (default or lsp)exclude_this=true, -- Exclude current buffer from operationsn_query=10, -- Number of queries to send for each operationnotify=true, -- Show notifications for operationstimeout_ms=5000, -- Timeout in milliseconds for operationson_setup= {
update=true, -- Update VectorCode on setuplsp=false, -- Disable automatic LSP startup during setup
},
sync_log_env_var=false, -- Don't sync environment variables for logging
}
)
vim.api.nvim_create_autocmd("LspAttach", {
callback=function()
localcacher=require("vectorcode.cacher")
localbufnr=vim.api.nvim_get_current_buf()
cacher.utils.async_check("config", function()
cacher.lsp.register_buffer(bufnr, {
-- provide rich context for LSP queriesn_query=10,
})
end, nil)
end,
desc="Register buffer for VectorCode",
})
end,
}

Solution

Before calling vim.lsp.buf_detach_client, check that the buffer is attached using vim.lsp.buf_is_attached

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.72%. Comparing base (56f21eb) to head (7e20d6a).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #303 +/- ##
=======================================
Coverage 99.72% 99.72% =======================================
Files 25 25 Lines 1845 1845 =======================================
Hits 1840 1840 Misses 5 5 

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[Davidyz]

Thanks for the contribution, and sorry for taking so long to process this. I was sick and couldn't take care of my Github.

[larrybotha]

no worries - thanks for the hard work, much appreciated!