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bug: published MCP server cannot start as an OMP plugin #123

Description

@vixygrey

Problem

Installing bigpowers@2.88.2 as an OMP user plugin causes this startup error:

MCP server failed to connect: bigpowers-mcp [.../.mcp.json]: ENOENT: no such file or directory, posix_spawn 'node'

Verified causes

  1. The published .mcp.json sets cwd to ${workspaceFolder}. OMP expands environment variables, but workspaceFolder is not an environment variable. OMP roots the unresolved relative value under the package directory. The resulting directory does not exist.
  2. After changing the working directory to the package root, the compiled server fails with ERR_MODULE_NOT_FOUND for @modelcontextprotocol/sdk. The root package does not declare the bigpowers-mcp runtime dependencies, and the published nested package has no node_modules directory.

Bun reports a missing working directory as ENOENT: ... posix_spawn 'node', so the first message incorrectly suggests that Node is absent.

Expected result

The published npm package starts its declared MCP server from an arbitrary OMP project without a separate dependency installation.

Possible package-side fixes:

  • Use a package-relative working directory or ${OMP_PLUGIN_ROOT}.
  • Bundle the MCP server, or include its runtime dependencies in the published install graph.
  • Add an installed-package smoke test that starts the server and completes MCP initialization.

Activity

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