mdx lsp failure with invalid glob error

[VisualEhrmanntraut]

Description

[ERROR][2026-05-01 12:57:24] /opt/local/share/nvim/runtime/lua/vim/lsp/log.lua:151	"LSP[mdx_analyzer]"	"on_error"	{ code = "SERVER_REQUEST_HANDLER_ERROR", err = "/opt/local/share/nvim/runtime/lua/vim/glob.lua:373: Invalid glob: **/*.{mdx}" }
[ERROR][2026-05-01 12:57:24] /opt/local/share/nvim/runtime/lua/vim/lsp/log.lua:151	"rpc"	"mdx-language-server"	"stderr"	"/Users/visual/Library/pnpm/store/v11/links/@/vscode-jsonrpc/8.2.0/8266e362a6a228f16976abb04d4343790994e96ac8e531c5bd35d3f8d8371de1/node_modules/vscode-jsonrpc/lib/common/connection.js:565\n                        responsePromise.reject(new messages_1.ResponseError(error.code, error.message, error.data));\n                                               ^\n\nResponseError: /opt/local/share/nvim/runtime/lua/vim/glob.lua:373: Invalid glob: **/*.{mdx}\n    at handleResponse (/Users/visual/Library/pnpm/store/v11/links/@/vscode-jsonrpc/8.2.0/8266e362a6a228f16976abb04d4343790994e96ac8e531c5bd35d3f8d8371de1/node_modules/vscode-jsonrpc/lib/common/connection.js:565:48)\n    at handleMessage (/Users/visual/Library/pnpm/store/v11/links/@/vscode-jsonrpc/8.2.0/8266e362a6a228f16976abb04d4343790994e96ac8e531c5bd35d3f8d8371de1/node_modules/vscode-jsonrpc/lib/common/connection.js:345:13)\n    at processMessageQueue (/Users/visual/Library/pnpm/store/v11/links/@/vscode-jsonrpc/8.2.0/8266e362a6a228f16976abb04d4343790994e96ac8e531c5bd35d3f8d8371de1/node_modules/vscode-jsonrpc/lib/common/connection.js:362:17)\n    at Immediate.<anonymous> (/Users/visual/Library/pnpm/store/v11/links/@/vscode-jsonrpc/8.2.0/8266e362a6a228f16976abb04d4343790994e96ac8e531c5bd35d3f8d8371de1/node_modules/vscode-jsonrpc/lib/common/connection.js:334:13)\n    at process.processImmediate (node:internal/timers:504:21) {\n  code: -32603,\n  data: undefined\n}\n\nNode.js v24.15.0\n"

# nvim -V1 -v   
NVIM v0.12.2
Build type: Release
LuaJIT 2.1.1774896198
Vim versions: 8.1, 8.2, 9.0, 9.1, 9.2

   system vimrc file: "$VIM/sysinit.vim"
  fall-back for $VIM: "/opt/local/share/nvim"

Run :checkhealth for more info

additionally, nothing happens when opening mdx files unless I do :setfiletype mdx

[justinmk]

hmm, we do have tests for globs like that here: https://github.com/neovim/neovim/blob/83ee06463b94895d024a69f2d7a03abe16f6147c/test/functional/lua/glob_spec.lua#L260-L264

cc @brynne8

[brynne8]

This behavior is actually intended for brace expansion. Since Neovim 0.12, the glob implementation (which I originally created) was updated and made stricter to align more closely with standards—you can see the details in neovim/neovim#33605.

As the code comments in https://github.com/neovim/neovim/blob/master/runtime/lua/vim/glob.lua#L28 explain:

--- `{}` (*braced conditions*) contains valid Glob patterns as branches,
--- separated by commas. Commas are exclusively used for separating
--- branches and cannot appear within a branch for any other purpose.
--- Nested `{}` structures are allowed, but `{}` must contain at least two
--- branches—zero or one branch is not permitted.

So patterns like **/*.{mdx} are considered invalid and won’t match /path/to/any.mdx. This follows the GNU Bash manual on brace expansion. Popular libraries like minimatch also reject this pattern, and you can see it in action using this interactive glob tester, which uses minimatch under the hood.

That said, there’s room for discussion—should LSPs adapt to this stricter standard, or should Neovim consider loosening the rules for more permissive patterns?

[justinmk]

should Neovim consider loosening the rules for more permissive patterns?

If it's possible, and compatible with LSP, then yes we should do what's intuitive and commonly expected.