Bug with incorrectly reporting undefined-global

So I have this very strange bug where the VSCode extension starts reporting undefined-globals but when I click on the actual problem report, it goes away.

These globals are defined in a file that is loaded as a library via an extension so I figured I might reach the max workspace files/size limit but even with those set to very high numbers it keeps happening. I can click on all of them to make them go away but the next indexing run (hitting save) will bring them back.

workspace.maxPreload is set to 20000
workspace.preloadFileSize is set to 8000

The repo I tested with is WeakAuras

https://user-images.githubusercontent.com/75278/202040021-d15fda8e-85ce-4055-a39e-d9538f6b5446.mp4

So my next guess was that the LSP just crashes and restarts, I checked the output panel and got this:

script/core/diagnostics/param-type-mismatch.lua:21: attempt to index a nil value (field 'generic')
stack traceback:
	script/core/diagnostics/param-type-mismatch.lua:21: in upvalue 'expandGenerics'
	script/core/diagnostics/param-type-mismatch.lua:48: in upvalue 'getDefNode'
	script/core/diagnostics/param-type-mismatch.lua:97: in local 'callback'
	script/parser/guide.lua:716: in function 'parser.guide.eachSourceType'
	script/core/diagnostics/param-type-mismatch.lua:83: in function 'core.diagnostics.param-type-mismatch'
	script/core/diagnostics/init.lua:117: in upvalue 'check'
	script/core/diagnostics/init.lua:174: in function 'core.diagnostics'
	[C]: in function 'xpcall'
	script/provider/diagnostic.lua:324: in function 'provider.diagnostic.doDiagnostic'
	[C]: in function 'xpcall'
	script/provider/diagnostic.lua:665: in upvalue 'callback'
	script/files.lua:880: in function <script/files.lua:879>
script/core/diagnostics/param-type-mismatch.lua:21: attempt to index a nil value (field 'generic')

使用 VSCode 扩展和报告中的工作区设置，在 WeakAuras 仓库中复现该问题。从 script/core/diagnostics/param-type-mismatch.lua 的第 21 行开始，沿着经过 script/provider/diagnostic.lua 的调用栈进行跟踪；当诊断索引不再崩溃，并且重新索引后未定义全局变量报告仍然正确时，即表示完成。