VS Code extension does not work with `subst` drive after VS Code update to 1.101.1

[PetSerAl]

I am not sure if that is this extension responsibility, but I have no effective means to investigate it further. After VS Code update to 1.101.1 extension does not work with subst drive. It previously worked with VS Code 1.100.3.

Environments

• IDE Version: VS Code
  Version: 1.101.1 (system setup)
  Commit: 18e3a1ec544e6907be1e944a94c496e302073435
  Date: 2025-06-18T13:35:12.605Z
  Electron: 35.5.1
  ElectronBuildId: 11727614
  Chromium: 134.0.6998.205
  Node.js: 22.15.1
  V8: 13.4.114.21-electron.0
  OS: Windows_NT x64 10.0.26100
• Extension Version: 2.0.6
• CSharpier Version: 1.0.2
• .csharpierrc Settings: none
• .editorconfig Settings: none

Log Output

["INFO" - 11:17:25 PM] Initializing csharpier-vscode
["ERROR" - 11:17:25 PM] Exception while trying to provide diagnostics
["ERROR" - 11:17:25 PM] ENOENT: no such file or directory, scandir 'm:\\'
Error: ENOENT: no such file or directory, scandir 'm:\\'
	at Object.readdirSync (node:fs:1585:26)
	at t.readdirSync (node:electron/js2c/node_init:2:16005)
	at p.CSharpierProcessProvider.findVersionInCsProj (c:\Users\Test\.vscode\extensions\csharpier.csharpier-vscode-2.0.6\build\Extension.js:2:64018)
	at p.CSharpierProcessProvider.findVersionInCsProjOfParentsDirectories (c:\Users\Test\.vscode\extensions\csharpier.csharpier-vscode-2.0.6\build\Extension.js:2:63847)
	at c:\Users\Test\.vscode\extensions\csharpier.csharpier-vscode-2.0.6\build\Extension.js:2:63012
	at p.runFunctionsUntilResultFound (c:\Users\Test\.vscode\extensions\csharpier.csharpier-vscode-2.0.6\build\Extension.js:2:87335)
	at p.CSharpierProcessProvider.getCSharpierVersion (c:\Users\Test\.vscode\extensions\csharpier.csharpier-vscode-2.0.6\build\Extension.js:2:63001)
	at p.CSharpierProcessProvider.findAndWarmProcess (c:\Users\Test\.vscode\extensions\csharpier.csharpier-vscode-2.0.6\build\Extension.js:2:66906)
	at p.CSharpierProcessProvider.getProcessFor (c:\Users\Test\.vscode\extensions\csharpier.csharpier-vscode-2.0.6\build\Extension.js:2:62277)
	at p.FormatDocumentProvider.formatDocument (c:\Users\Test\.vscode\extensions\csharpier.csharpier-vscode-2.0.6\build\Extension.js:2:80192)
	at s.runDiagnostics (c:\Users\Test\.vscode\extensions\csharpier.csharpier-vscode-2.0.6\build\Extension.js:2:73898)
	at s.registerEditorEvents (c:\Users\Test\.vscode\extensions\csharpier.csharpier-vscode-2.0.6\build\Extension.js:2:73009)
	at new s (c:\Users\Test\.vscode\extensions\csharpier.csharpier-vscode-2.0.6\build\Extension.js:2:72786)
	at h (c:\Users\Test\.vscode\extensions\csharpier.csharpier-vscode-2.0.6\build\Extension.js:2:78096)
	at process.processTicksAndRejections (node:internal/process/task_queues:105:5)
	at async p.activate (c:\Users\Test\.vscode\extensions\csharpier.csharpier-vscode-2.0.6\build\Extension.js:2:77228)
	at async Wb.n (file:///c:/Program%20Files/Microsoft%20VS%20Code/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:120:13382)
	at async Wb.m (file:///c:/Program%20Files/Microsoft%20VS%20Code/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:120:13345)
	at async Wb.l (file:///c:/Program%20Files/Microsoft%20VS%20Code/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:120:12801)

Steps to reproduce

rem Current directory is C:\Users\Test
md Code
echo class C {  }>Code\Test.cs
rem This works
"C:\Program Files\Microsoft VS Code\bin\code.cmd" Code
subst M: C:\Users\Test
rem This does not works
"C:\Program Files\Microsoft VS Code\bin\code.cmd" M:\Code

[belav]

It isn't clear why node can't read files from the root of the virtual drive. I wrapped that code in a try catch so assuming the actual project someone is working with is in a sub directory of the virtual drive then CSharpier will work like you'd expect.

2.0.7 has the fix and will be available shortly. Thanks for reporting the issue!

[PetSerAl]

Thank you for quick fix.
Tried to dig dipper. It seems issue related with double backslash in error message: m:\\.

But as long as I can trace Csharpier extension pass m:\ to readdirSync. So look like node.js internal path handling clobber path by doubling last backslash.

[belav]

Tried to dig dipper. It seems issue related with double backslash in error message: m:\.

I was hoping that would allow me to strip double slashes to get this working, but it seems node is still unhappy trying to read anything from the root of m even though it does think that it exists

[PetSerAl]

It seems to work when written like this:

fs.readdirSync("M:\\.")