Copilot always tries unix command before PowerShell

[gustavlarson]

Describe the bug

I'm running copilot-cli on Windows in PowerShell.
I have the following in my custom-instructions.md file:

- Assume that you are running in a Windows environment.
- Any shell or terminal commands/syntax should be PowerShell native commands and any paths should use Windows-style backslashes.
- DO NOT use Unix/Linux-style commands or paths unless explicitly instructed otherwise.

However, copilot almost always tries to use Unix/Linux shell commands like grep, head, wc, etc, before trying PowerShell.

Example:

✔ List build errors by file
$ dotnet build --nologo --tl:off 2>&1 | grep ".cs(" | head -20
└ 7 lines...

✔ List build errors by file
$ dotnet build --nologo --tl:off 2>&1 | Select-String ".cs(" | Select-Object -First 20

Affected version

0.0.365

Steps to reproduce the behavior

No response

Expected behavior

Copilot CLI understanding that it is running in a Windows PowerShell environment and using PowerShell command instead of Unix/Linux style commands

Additional context

No response