Cannot Apply Diff – Target Path is a Directory Instead of a File (Dev Containers)

[giannoug]

App Version

3.16.5

API Provider

OpenRouter

Model Used

anthropic/claude-3.7-sonnet

🔁 Steps to Reproduce

Applying a diff in a Dev Container fails with the following error:

Error applying diff:
cannot open vscode-remote://dev-container%(some alphanumeric here)/workspaces/myproject/my-microservice. Detail: Unable to read file 'vscode-remote://dev-container+(some alphanumeric here)/workspaces/myproject/my-microservice' (Error: Unable to read file 'vscode-remote://dev-container+(some alphanumeric here)/workspaces/myproject/my-microservice' that is actually a directory)

After this failure, Roo attempts to apply the change using the write_to_file tool:

Let's try using the write_to_file tool instead to update the xxx.java file.

Let's try using the write_to_file tool instead to update the xxx.java file. First, let's read the current content of the file.

This approach succeeded in this instance, but I’ve seen cases where even write_to_file fails. When that happens, Roo eventually resorts to using sed to make the changes, which does succeed.

Environment:

• Windows 11
• WSL2 (default Ubuntu distro)
• VS Code with Dev Containers

Notes: I'm not sure how to reproduce this consistently—it seems to occur after the environment has been running for a while (>1d). It's unclear whether the issue lies with Roo, VS Code's Dev Containers extension, or something else in the toolchain.

I'm primarily opening this issue in case others encounter the same behavior. I'm happy to provide additional information if I discover more.

💥 Outcome Summary (Optional)

Roo failed to apply a diff because it tried to treat a directory as a file (allegedly); fallback methods eventually worked, but the root cause remains unclear and intermittent.

📄 Relevant Logs or Errors

[dosubot[bot]]

The issue you're encountering seems to be related to how Roo Code handles file paths within VS Code's Dev Containers. The error message indicates that Roo Code is attempting to apply a diff to a path that is recognized as a directory rather than a file. This can happen due to discrepancies in how paths are resolved in the Dev Container environment.

Currently, there isn't specific documentation available on how Roo Code determines whether a target path is a file or a directory when applying diffs . However, the fallback mechanism you described, where Roo Code uses the write_to_file tool and eventually resorts to sed, is a known behavior. The write_to_file tool has limitations, especially with existing files and large files, and is not suitable for automated workflows as it is interactive only ^[1][2].

Given the intermittent nature of the issue, it might be related to the state of the Dev Container environment after it has been running for an extended period. This could involve caching issues or temporary file system states that affect path resolution.

To further investigate, you might want to:

• Check if there are any updates or known issues with the VS Code Dev Containers extension that could affect file path recognition.
• Monitor the environment variables and settings within the Dev Container that might influence Roo Code's behavior.

If the problem persists, consider documenting any additional patterns or conditions under which the issue occurs, as this information could be valuable for troubleshooting or reporting a bug.

To continue talking to Dosu, mention @dosu.

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