bug: Invalid input: must start with "file://" error on start with VSCode and WSL #1153
Description
Description
Starting the MCP server on VSCode in a WSL environment shows an error and Taskmaster tools are not recognised in Copilot.
Steps to Reproduce
- Run
npm i task-master-ai@latest -gin WSL terminal - Add taskmaster MCP server to
.vscode/mcp.json:
{
"servers": {
"taskmaster-ai": {
"command": "npx",
"args": ["-y", "--package=task-master-ai", "task-master-ai"],
"env": {
"OPENAI_API_KEY": "${env:OPENAI_API_KEY}",
},
"type": "stdio"
}
}
}- Run command MCP: Show Installed Servers.
- Right click the taskmaster-ai listing and select Restart Server.
- Open Copilot chat and run the get-tasks tool
- Prompt Copilot to get the current tasks
Expected Behavior
- Errors are not shown in the MCP Server start output
- Prompts and tools related to task master tasks are recognised
Actual Behavior
- Copilot doesn't understand taskmaster tool.
- MCP: taskmaster-ai output shows an error.
Screenshots or Logs
Invalid input: must start with "file://" error in the MCP: taskmaster-ai output.
2025-08-23 08:15:57.980 [info] Starting server taskmaster-ai
2025-08-23 08:15:57.981 [info] Connection state: Starting
2025-08-23 08:15:57.981 [info] Starting server from Remote extension host
2025-08-23 08:15:57.991 [info] Connection state: Starting
2025-08-23 08:15:57.991 [info] Connection state: Running
2025-08-23 08:15:59.901 [info] Discovered 36 tools
2025-08-23 08:15:59.956 [warning] [server stderr] [FastMCP error] received error listing roots.
2025-08-23 08:15:59.957 [warning] [server stderr]
2025-08-23 08:15:59.957 [warning] [server stderr] ZodError: [
2025-08-23 08:15:59.957 [warning] [server stderr] {
2025-08-23 08:15:59.958 [warning] [server stderr] "code": "invalid_string",
2025-08-23 08:15:59.958 [warning] [server stderr] "validation": {
2025-08-23 08:15:59.958 [warning] [server stderr] "startsWith": "file://"
2025-08-23 08:15:59.958 [warning] [server stderr] },
2025-08-23 08:15:59.959 [warning] [server stderr] "message": "Invalid input: must start with \"file://\"",
2025-08-23 08:15:59.959 [warning] [server stderr] "path": [
2025-08-23 08:15:59.959 [warning] [server stderr] "roots",
2025-08-23 08:15:59.960 [warning] [server stderr] 0,
2025-08-23 08:15:59.960 [warning] [server stderr] "uri"
2025-08-23 08:15:59.960 [warning] [server stderr] ]
2025-08-23 08:15:59.960 [warning] [server stderr] }
2025-08-23 08:15:59.960 [warning] [server stderr] ]
2025-08-23 08:15:59.961 [warning] [server stderr] at get error (file:///home/user/.npm/_npx/0726791833487271/node_modules/zod/v3/types.js:39:31)
2025-08-23 08:15:59.961 [warning] [server stderr] at ZodObject.parse (file:///home/user/.npm/_npx/0726791833487271/node_modules/zod/v3/types.js:114:22)
2025-08-23 08:15:59.961 [warning] [server stderr] at file:///home/user/.npm/_npx/0726791833487271/node_modules/@modelcontextprotocol/sdk/dist/esm/shared/protocol.js:294:49
2025-08-23 08:15:59.961 [warning] [server stderr] at Server._onresponse (file:///home/user/.npm/_npx/0726791833487271/node_modules/@modelcontextprotocol/sdk/dist/esm/shared/protocol.js:220:13)
2025-08-23 08:15:59.961 [warning] [server stderr] at _transport.onmessage (file:///home/user/.npm/_npx/0726791833487271/node_modules/@modelcontextprotocol/sdk/dist/esm/shared/protocol.js:84:22)
2025-08-23 08:15:59.962 [warning] [server stderr] at StdioServerTransport.processReadBuffer (file:///home/user/.npm/_npx/0726791833487271/node_modules/@modelcontextprotocol/sdk/dist/esm/server/stdio.js:43:79)
2025-08-23 08:15:59.962 [warning] [server stderr] at StdioServerTransport._ondata (file:///home/user/.npm/_npx/0726791833487271/node_modules/@modelcontextprotocol/sdk/dist/esm/server/stdio.js:17:18)
2025-08-23 08:15:59.962 [warning] [server stderr] at Socket.emit (node:events:518:28)
2025-08-23 08:15:59.962 [warning] [server stderr] at addChunk (node:internal/streams/readable:561:12)
2025-08-23 08:15:59.963 [warning] [server stderr] at readableAddChunkPushByteMode (node:internal/streams/readable:512:3)
2025-08-23 08:15:59.964 [info] {"message":"MCP Server connected: undefined"}
2025-08-23 08:15:59.964 [info] {"message":"MCP Server connected"}
get-tasks response
Responses to running the get-tasks tool in Copilot:
What would you like me to do in /home/user/src/project? Choose one:
- list files in the repo root
- open or edit a specific file (tell me the path)
- run tests or show how to run them
- scaffold a new file or change existing code
- review the active editor contents (paste or tell filename)
To list files in the project root, run:
ls -la /home/user/src/projectIf you want a recursive listing:
ls -laR /home/user/src/project | sed -n '1,200p'Copilot prompt
Input Copilot prompt:
get the taskmaster tasks
GitHub Copilot response:
Do you mean "Taskmaster" tasks defined in this repository, or tasks managed by a system tool? Tell me which and I can inspect files or run commands. Meanwhile, you can run these to find task definitions in /home/user/src/project:
# search for "taskmaster" mentions
grep -RIn "taskmaster" /home/user/src/project || true
Environment
- Task Master version: 0.25.0
- Node.js version: v22.15.0
- Operating system: Ubuntu 22.04 (WSL distro)
- IDE (if applicable): VSCode 1.103.2 (below)
Version: 1.103.2 (user setup)
Commit: 6f17636121051a53c88d3e605c491d22af2ba755
Date: 2025-08-20T16:45:34.255Z
Electron: 37.2.3
ElectronBuildId: 12035395
Chromium: 138.0.7204.100
Node.js: 22.17.0
V8: 13.8.500258-electron.0
OS: Windows_NT x64 10.0.26100
Additional Context
The same Taskmaster setup is working fine in Cursor 1.4.5. but I am trying VSCode since Cursor issue https://forum.cursor.com/t/run-command-often-freezes/123357 makes progress with Cursor difficult.