On Unix, ripgrep ignores stdin input provided via .NET 5.0 APIs

[mklement0]

What version of ripgrep are you using?

ripgrep 12.1.1

How did you install ripgrep?

Homebrew on macOS, snap on Ubuntu (latest version there is 12.1.0).

What operating system are you using ripgrep on?

macOS 10.15.7
Ubuntu 18.04

Describe your bug.

rg ignores stdin input provided via .NET 5.0 APIs (no other programs I'm aware of have this problem; e.g., grep works fine). Windows is not affected.

What are the steps to reproduce the behavior?

PowerShell 7.1:

$psi = [System.Diagnostics.ProcessStartInfo] @{
  FileName = 'rg'
  RedirectStandardInput = $true
  Arguments = 'hi'
}

$ps = [System.Diagnostics.Process]::Start($psi)

$ps.StandardInput.WriteLine('hi there');
$ps.StandardInput.Close()

$ps.WaitForExit()

C# with .NET 5.0.101 SDK:

using System;
using System.Diagnostics;

namespace demo
{
  static class ConsoleApp
  {
    static void Main(string[] args)
    {
      var psi = new ProcessStartInfo { FileName = "rg", RedirectStandardInput = true, Arguments = "hi" };
      var ps = Process.Start(psi);

      ps.StandardInput.WriteLine("hi there");
      ps.StandardInput.Close();

      ps.WaitForExit();

    }

  }
}

What is the actual behavior?

rg behaves as if no stdin input had been specified and searches through the files in the current directory subtree.

What is the expected behavior?

The output should be hi there, just like when you run echo 'hi there' | rg hi from any POSIX-like shell.

However, since PowerShell [Core] is built on .NET, this command does not work in PowerShell v7.1

[BurntSushi]

This looks like a duplicate of #1741, which was fixed by #1742.

Also note that I do not recommend using Snap to install ripgrep. It has resulted in all sorts of weird problems. (Searching the issue tracker should turn up prior discussions.)