Docker Image 1.0.2 Breaks Linux Users with Letter at Start of Path

[jvanvolken]

Describe the bug
This 1.0.2 breaks linux users who's paths start with a letter. i.e. /h/path/to/data. We were very confused when our linux paths were converted to windows paths:

This error does not happen with mcp/filesystem:sha256-35fcf0217ca0d5bf7b0a5bd68fb3b89e08174676c0e0b4f431604512cf7b3f67; it only happens with mcp/filesystem:1.0.2.

To Reproduce
Steps to reproduce the behavior:

1. Docker pull mcp/filesystem:1.0.2
2. Configure with a linux path that starts with a /h/ or other letter
3. Start up mcp server

Expected behavior
Should mount the correct path without changing it.

Logs
This is the error when the gateway tries to configure the mcp server:
Running mcp/filesystem:1.0.2 with [run --rm -i --init --security-opt no-new-privileges --cpus 1 --memory 2Gb --pull never -l docker-mcp=true -l docker-mcp-tool-type=mcp -l docker-mcp-name=filesystem -l docker-mcp-transport=stdio --network none -v /h/<username>/MCP_Development/data:/h/<username>/MCP_Development/data] and command [/h/<username>/MCP_Development/data]

mcp-gateway  | - filesystem: Error accessing directory H:\<username>\MCP_Development\data: Error: ENOENT: no such file or directory, stat 'H:\<username>\MCP_Development\data'
mcp-gateway  | - filesystem:     at async Object.stat (node:internal/fs/promises:1039:18)
mcp-gateway  | - filesystem:     at async file:///app/dist/index.js:44:23
mcp-gateway  | - filesystem:     at async Promise.all (index 0)
mcp-gateway  | - filesystem:     at async file:///app/dist/index.js:42:1 {
mcp-gateway  | - filesystem:   errno: -2,
mcp-gateway  | - filesystem:   code: 'ENOENT',
mcp-gateway  | - filesystem:   syscall: 'stat',
mcp-gateway  | - filesystem:   path: 'H:\\<username>\\MCP_Development\\data'
mcp-gateway  | - filesystem: }
mcp-gateway  |   > Can't start filesystem: failed to connect: calling "initialize": EOF

Additional context
N/A

[owendevereaux]

I investigated this issue and found something interesting:

Looking at the current path-utils.ts on main, the code appears to handle Linux paths correctly:

const isUnixPath = p.startsWith('/') && (
  p.match(/^\/mnt\/[a-z]\//i) ||
  (process.platform !== 'win32') ||  // Should be TRUE in Linux Docker
  ...
);

On a Linux Docker container, process.platform === 'linux', so the condition (process.platform !== 'win32') should be true, which should preserve Unix paths like /h/username/... without converting them to Windows format.

Question: Is there a chance the mcp/filesystem:1.0.2 Docker image was built from an older version of the code that didn't have this platform detection logic? The fix may already exist on main but not be in the released Docker image.

If so, rebuilding the Docker image from the current main branch might resolve this issue.

(I noticed the package tags are typescript-servers-0.6.x while the Docker image uses 1.0.2 versioning, so there may be a versioning/release pipeline difference.)