Duplicate identifier errors when using @types inside a Windows junction

This is a dupe of #11333, but that issue was marked as closed/fixed (and locked… why?). It’s not. It should be reopened and actually fixed. It’s also unrelated to ‘npm link’.

IMPORTANT:

my e:\work directory is a JUNCTION point to y:\work

node: 13.5.0 npm: 6.13.4 tsc: 3.7.5

index.ts:

/// <reference path="node_modules/@types/youtube/index.d.ts" />

package.json:

{
  "name": "junction-bug",
  "scripts": {
    "tsc": "tsc index.ts"
  },
  "devDependencies": {
    "@types/youtube": "0.0.38",
    "typescript": "^3.7.5"
  }
}

NOTE: There is NO reference to ‘y:’ in any of my project’s files, nor in any of npm’s files. tsc is erroneously converting relative paths to absolute paths on the destination drive. look for references to y:\ in the output below:

e:\work\junction-bug>dir e:\ | findstr work
04/19/2016  09:02 AM    <JUNCTION>     work [y:\work]

e:\work\junction-bug>npm i
...
e:\work\junction-bug>findstr /s /i /c:"y:\\" *

e:\work\junction-bug>npm run tsc

> junction-bug@ tsc E:\work\junction-bug
> tsc index.ts

node_modules/@types/youtube/index.d.ts:16:1 - error TS6200: Definitions of the following identifiers conflict with those in another file: UNSTARTED, ENDED, PLAYING, PAUSED, BUFFERING, CUED, InvalidParam, Html5Error, VideoNotFound, EmbeddingNotAllowed, EmbeddingNotAllowed2, AlwaysVisible, HideAllControls, HideProgressBar, NoAutoPlay, AutoPlay, UserDefault, ForceOn, ProgressBarColor, Hide, ShowLoadPlayer, ShowDelayLoadPlayer, Enable, Disable, Show, ListType, ListTypePlayer, ListTypeSearch, ListTypeUserUploads, SinglePlay, Loop, Full, Modest, Fullscreen, Inline, SuggestedVideoQuality, VideoQualityDefault, VideoQualitySmall, VideoQualityMedium, VideoQualityLarge, VideoQualityHD720, VideoQualityHD1080, VideoQualityHighRes, Player

16 declare namespace YT
   ~~~~~~~

  y:/work/junction-bug/node_modules/@types/youtube/index.d.ts:16:1
    16 declare namespace YT
       ~~~~~~~
    Conflicts are in this file.

y:/work/junction-bug/node_modules/@types/youtube/index.d.ts:16:1 - error TS6200: Definitions of the following identifiers conflict with those in 
another file: UNSTARTED, ENDED, PLAYING, PAUSED, BUFFERING, CUED, InvalidParam, Html5Error, VideoNotFound, EmbeddingNotAllowed, EmbeddingNotAllowed2, AlwaysVisible, HideAllControls, HideProgressBar, NoAutoPlay, AutoPlay, UserDefault, ForceOn, ProgressBarColor, Hide, ShowLoadPlayer, ShowDelayLoadPlayer, Enable, Disable, Show, ListType, ListTypePlayer, ListTypeSearch, ListTypeUserUploads, SinglePlay, Loop, Full, Modest, Fullscreen, Inline, SuggestedVideoQuality, VideoQualityDefault, VideoQualitySmall, VideoQualityMedium, VideoQualityLarge, VideoQualityHD720, VideoQualityHD1080, VideoQualityHighRes, Player

16 declare namespace YT
   ~~~~~~~

  node_modules/@types/youtube/index.d.ts:16:1
    16 declare namespace YT
       ~~~~~~~
    Conflicts are in this file.


Found 2 errors.

Related Issues: 113333

[Bosch-Eli-Black]

@minestarks Upgrading to VS 17.2 Preview 2 fixed our issue 🙂 Thanks again for your help!

[minestarks]

Got it. I’m able to repro with @Spongman 's repro steps. There does seem to be a bug as to how we handle junctions.

@Bosch-Eli-Black I think your repro is the victim of multiple different bugs - one, as I mentioned, is fixed in the next update the VS. The second one, where we included a lot of unnecessary typings (which caused all the unnecessary errors) was fixed in #47164 , which is in TS 4.6, which is also bundled in the next update to VS. With these two fixed, I think you won’t even hit the third one, which is this bug 😃