Bug: LSP server spawn doesn't use the same PATH resolution as isServerInstalled()

[aaajiao]

Summary

isServerInstalled() checks 4 additional paths beyond $PATH (including cwd/node_modules/.bin/), but spawnProcess() only uses process.env.PATH. This causes LSP servers that are detected as "installed" to fail at spawn time with a "not found" error.

Reproduction

1. Install biome as a project dependency: npm install @biomejs/biome
2. Do NOT install biome globally
3. Confirm binary exists: ls ./node_modules/.bin/biome → exists
4. Run lsp_diagnostics on a .ts file
5. Expected: biome LSP starts successfully (since isServerInstalled finds it in node_modules/.bin/)
6. Actual: Error: Executable not found in $PATH: "biome"

Root Cause

Detection (server-installation.ts → isServerInstalled)

Checks these paths (broad):

// 1. System PATH
// 2. cwd/node_modules/.bin/        ← finds biome here ✅
// 3. configDir/bin/
// 4. configDir/node_modules/.bin/
// 5. dataDir/bin/

Spawn (lsp-client-transport.ts → start())

Uses only process.env (narrow):

this.proc = spawnProcess(this.server.command, {
    cwd: this.root,
    env: {
        ...process.env,        // ← only system PATH, no additionalBases
        ...this.server.env
    }
});

The additionalBases from isServerInstalled are completely ignored during spawn.

Suggested Fix

In lsp-client-transport.ts, augment the spawn env's PATH with the same additional paths that isServerInstalled checks:

// Option A: Add node_modules/.bin to spawn PATH
const extraPaths = [
    path.join(this.root, "node_modules", ".bin"),
    path.join(configDir, "bin"),
    path.join(configDir, "node_modules", ".bin"),
    path.join(dataDir, "bin"),
];
const augmentedPath = [...extraPaths, process.env.PATH].filter(Boolean).join(":");

this.proc = spawnProcess(this.server.command, {
    cwd: this.root,
    env: {
        ...process.env,
        ...this.server.env,
        PATH: augmentedPath,
    }
});

Or alternatively, resolve the full binary path in isServerInstalled and pass the absolute path to spawn.

Environment

• oh-my-opencode version: latest (as of 2026-03-10)
• Runtime: Bun (Linux arm64, Docker)
• Affected server: biome (but applies to any LSP server installed only in node_modules/.bin/)

[code-yeongyu]

[sisyphus-bot] Confirmed Bug — P2

Root Cause

isServerInstalled() in src/tools/lsp/server-installation.ts checks additional paths beyond $PATH (including cwd/node_modules/.bin/, configDir/bin/, dataDir/bin/), but spawnProcess() in src/tools/lsp/lsp-client-transport.ts only uses process.env.PATH.

This means a binary can be detected as "installed" but fail to spawn with ENOENT because those extra directories are not in the spawn environment's PATH.

Affected Files

• src/tools/lsp/server-installation.ts — checks extra paths (lines 48-53)
• src/tools/lsp/lsp-client-transport.ts — spawn uses only process.env.PATH (lines 23-27)
• src/tools/lsp/lsp-process.ts — spawns with provided env unchanged (lines 153-159)

Fix Approach

Option A — Augment spawn PATH with same extra bases:

const extraPaths = [
  path.join(this.root, "node_modules", ".bin"),
  path.join(configDir, "bin"),
  path.join(configDir, "node_modules", ".bin"),
  path.join(dataDir, "bin"),
]
const augmentedPath = [...extraPaths, process.env.PATH].filter(Boolean).join(path.delimiter)

this.proc = spawnProcess(this.server.command, {
  env: { ...process.env, ...this.server.env, PATH: augmentedPath }
})

Option B — Resolve to absolute path in isServerInstalled() and pass the full path to spawn (cleaner, avoids PATH manipulation).