Bug: Include the invalid path when workspace additional-directory validation fails #4147

What version of Kimi Code is running?

2.1.1

Which open platform/subscription were you using?

N/A. This occurs during local workspace configuration or ACP session setup, before any provider request.

Which model were you using?

N/A. The error occurs before a model request.

What platform is your computer?

Linux 7.2.9-200.nobara.fc44.x86_64 x86_64 unknown

What issue are you seeing?

Kimi reports this error when an additional workspace directory is unavailable:

workspace.additional_dir must exist and be a directory

The message does not include the invalid path.

This affects both project-local configuration and ACP:

• A project can contain one or more invalid entries in .kimi-code/local.toml.
• An ACP client can send session/new.params.additionalDirectories. Kimi advertises support for this capability, but an IDE does not necessarily show users which paths it sent. Diagnosing a missing path currently requires capturing ACP traffic.

In either case, users cannot identify the offending directory from the Kimi error.

What steps can reproduce the bug?

Project-local configuration

From a Git repository, create .kimi-code/local.toml:

[workspace]
additional_dir = ["/tmp/kimi-directory-that-does-not-exist"]

Start Kimi from that repository.

ACP session setup

1. Start Kimi in ACP mode:

   kimi acp

2. Send initialize. Kimi advertises support for additional directories.

3. Send session/new with a valid cwd and an unavailable additional directory:

   {
     "jsonrpc": "2.0",
     "id": 2,
     "method": "session/new",
     "params": {
       "cwd": "/path/to/project",
       "mcpServers": [],
       "additionalDirectories": [
         "/path/that-is-not-available-to-kimi"
       ]
     }
   }

4. Kimi returns the generic error without identifying the path.

What is the expected behavior?

The error should include the resolved invalid path, for example:

workspace.additional_dir must exist and be a directory: /path/that-is-not-available-to-kimi

An empty additional-directory value should report that the value is empty.

Additional information

I encountered this through JetBrains AI Assistant using Kimi via aicage, which runs the agent in a container.

JetBrains sent an additional directory that was valid on the host but unavailable inside the container.
The same missing-path diagnostic also affects non-containerized project-local configuration.

Contribution

• I am willing to submit a PR for this bug fix myself (please wait for maintainer approval in this issue first)