Unversioned Files lists nonexistent files on Linux/macOS: "Cannot show diff: file not found"

Problem

The Git Unversioned Files list in Rider (or any IntelliJ-based IDE) shows files that do not exist anywhere on disk. These files cannot be removed from the list, and selecting one to view its diff results in the Cannot show diff: file not found error. The listed paths often appear under directories that should already be excluded by .gitignore (such as bin/ or obj/).

Cause

On Linux and macOS, the backslash (\) is a valid character in file and directory names. When an external tool is invoked with a Windows-style path — for example, dotnet ef called with bin\Debug\... — the tool creates a single directory whose literal name contains a backslash (bin\Debug) instead of the nested directories bin/Debug.

A .gitignore rule such as bin/ excludes the bin/ directory but does not match a top-level directory whose name contains a backslash. Git therefore treats those files as untracked, and the IDE displays them in the Unversioned Files list. Because the literal on-disk path contains a character that the IDE renders as a path separator, the diff viewer cannot resolve the file and reports Cannot show diff: file not found.

Resolution

1. Open a terminal in the project root and run git status to see the actual on-disk paths Git is tracking. Look for entries that contain literal backslashes, for example:

   Untracked files:
     bin\Debug\net8.0\appsettings.Development.json
   

2. List the offending entry from the shell (the backslash must be quoted or escaped):

   ls -la 'bin\Debug'
   

3. Remove the literal-backslash directory:

   rm -rf 'bin\Debug'
   

4. In the IDE, invoke File | Reload All from Disk (or refresh the Commit tool window). The phantom entries no longer appear.

5. To prevent recurrence, identify the tool that produced the path and run it with POSIX-style separators (/), or update the tool to a version where the issue is fixed. For dotnet ef, ensure the working directory and any --project / --output-dir arguments use forward slashes.

Additional information

• Files with literal backslashes in their names cannot be matched by standard .gitignore rules that use /. Adjust the producing tool rather than adding workaround .gitignore patterns.
• The same behavior applies to all IntelliJ-based IDEs (IntelliJ IDEA, Rider, PyCharm, WebStorm, GoLand, PhpStorm) on Linux and macOS.