"Command line too long" error in C# 1.20.0 because of "files.exclude" setting

[stefanhamburger]

With the new feature to ignore all files in the files.exclude setting (#2171), projects will no longer load if too many files are exluded.

In my case, the files.exclude setting is around 6,400 characters long (depending on how it is serialized), which results in an error because the OmniSharp command line is too long.

According to this Windows support article, the maximum length is 8,191 characters and the only workaround is to pass the data via a local file instead.

As a workaround, users can downgrade to version 1.19.1 or shorten the number of files in their files.exclude setting.

Environment data

• OS Name: Windows
• OS Version: 10.0.18362
• OS Platform: Windows
• RID: win10-x64
• VS Code version: 1.35.1
• C# Extension version: 1.20.0

Steps to reproduce

• Open a C# workspace in VS Code with a very long list of files and folders in the files.exclude setting.

Expected behavior

• The project should load as expected.

Actual behavior

• The following error message appears:

Starting OmniSharp server at 2019-6-19 09:33:43
    Target: d:\…\….sln

OmniSharp server started.
    Path: C:\Users\…\.vscode\extensions\ms-vscode.csharp-1.20.0\.omnisharp\1.32.20\OmniSharp.exe
    PID: 5076

Command line too long.

[rchande]

@stefanhamburger That's an amazing find. You can work around this by putting your exclude files in omnisharp.json (https://github.com/OmniSharp/omnisharp-roslyn/wiki/Configuration-Options) instead of in your VS Code settings. Obviously that won't help if you need those exclusions in VS Code too.

[kthy]

Yeah, no, that's not a workaround. I put the files in settings.json for a reason (namely that microsoft/vscode#38878 still isn't fixed).

[JoeRobich]

Closing as it appears the referenced VS Code PR has merged so that .gitignore can be used to hide files in the VS Code file explorer.