Remove hardcoded --cd ~ from WSL terminal fragment profiles to support Terminal's startingDirectory

[Copilot]

WSL was generating terminal fragment profiles with hardcoded --cd ~ arguments in the command line, which prevented Windows Terminal from being able to override the starting directory using its startingDirectory setting.

Problem

When WSL creates fragment profiles for Windows Terminal, it was generating command lines like:

C:\Windows\System32\wsl.exe --distribution-id {guid} --cd ~

This hardcoded --cd ~ argument overrides any startingDirectory setting that users configure in Windows Terminal, making it impossible to start WSL distributions in directories other than the home directory.

Solution

The fix removes the hardcoded --cd ~ arguments from the command line and instead ensures the fragment profile includes "startingDirectory": "~" in the JSON. This allows Windows Terminal to:

1. Use the default behavior (starting in ~) when no override is specified
2. Override the starting directory when users configure startingDirectory in their Terminal settings

Changes

• Command line generation: Removed WSL_CHANGE_DIRECTORY_ARG and WSL_CWD_HOME from the terminal profile command line
• JSON profile: Added logic to set "startingDirectory": "~" if not already specified by custom distribution templates
• Tests: Updated unit tests to verify the new command line format and presence of startingDirectory property

Behavior

Before:

{
  "commandline": "C:\\Windows\\System32\\wsl.exe --distribution-id {guid} --cd ~"
}

After:

{
  "commandline": "C:\\Windows\\System32\\wsl.exe --distribution-id {guid}",
  "startingDirectory": "~"
}

The fix preserves backward compatibility while enabling Terminal's startingDirectory functionality. Desktop shortcuts continue to work correctly as they still use --cd ~ (which is appropriate for shortcuts).

Fixes #13346.

---

💬 Share your feedback on Copilot coding agent for the chance to win a $200 gift card! Click here to start the survey.

[Copilot]

@benhillis 👋 This repository doesn't have Copilot instructions. With Copilot instructions, I can understand the repository better, work faster and produce higher quality PRs.

I can generate a .github/copilot-instructions.md file for you automatically. Click here to open a pre-filled issue and assign it to me. I'll write the instructions, and then tag you for review.

[benhillis]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[benhillis]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[benhillis]

@DHowett - is this what you had in mind?

[DHowett]

@benhillis looks good to me!

[OneBlue]

@DHowett: Does terminal know how to translate '~' to the proper path ?

[OneBlue]

Looks like there's special handling which, if I'm reading it correctly, will default to the Windows home directory

[DHowett]

Terminal passes ~ through to WSL if it knows it's launching WSL (per the comment below the linked line)

TL;DR: Terminal does not translate ~ at all if WSL is involved. It passes it along as --cd "~"

[DHowett]

The line you linked is solidly after all of the WSL --cd promotion attempts fail :)