Error: Request textDocument/signatureHelp failed.

How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

Which OS are you using?

Windows

What is the issue affecting?

Completion

Expected Behaviour

VSCode shows function arguments normally.

Actual Behaviour

"Request textDocument/signatureHelp failed" is shown.

[Error - 4:54:31 PM] Request textDocument/signatureHelp failed.
  Message: [16:54:31.780][error][#0:script\core\signature.lua:56]: script\core\signature.lua:56: attempt to index a nil value (local 'argLabel')
stack traceback:
	script\core\signature.lua:56: in upvalue 'makeOneSignature'
	script\core\signature.lua:175: in upvalue 'makeSignatures'
	script\core\signature.lua:209: in function 'core.signature'
	script\provider\provider.lua:783: in function <script\provider\provider.lua:770>
	[C]: in function 'xpcall'
	script\proto\proto.lua:202: in function <script\proto\proto.lua:177>

  Code: -32603 

Reproduction steps

Test code:

---@class ColorClass
local Color = {}

---@alias Color ColorClass|number[]
---@alias AlignMode
---| "center"
---| "left"
---| "right"
---| "justify"

---@param args string|{text:string,wrap:boolean?,font:{path:string,size:integer}?,scale:number?,align:AlignMode?,color:Color?,outline:number?,outlineColor:Color?}
local function fooz(args)
end

The args has to be quite long to trigger it and perhaps with that specific setup of Color and AlignMode too.

Afterwards, simply write fooz( on the next line and the error should appear.

Additional Notes

No response

Log File

file_d%3A_Data_Development_love-11.3-win64_luals-report.log

通过输入 fooz( 并请求签名帮助，使用 Lua 代码片段重现该故障。从 script/core/signature.lua:56 开始，然后跟踪 traceback 中显示的 makeSignatures 和 provider 调用帧。请求不再报错，并且 VS Code 显示此声明的函数参数，即表示完成。