import fs from 'node:fs';
import path from 'node:path';
import { spawnSync } from 'node:child_process';
/**
* Check if a Python installation has debugpy installed.
*/
function hasDebugpy(pythonExe: string): boolean {
try {
const result = spawnSync(pythonExe, ['-m', 'debugpy', '--version'], {
timeout: 5000,
stdio: 'pipe',
windowsHide: true,
});
return result.status === 0;
} catch {
return false;
}
}
function installDebugpy(pythonExe: string): { installed: boolean; log: string } {
try {
const result = spawnSync(
pythonExe,
['-m', 'pip', 'install', '--user', '--upgrade', 'debugpy'],
{
timeout: 120_000,
stdio: 'pipe',
windowsHide: true,
}
);
const log = (result.stdout?.toString() ?? '') + (result.stderr?.toString() ?? '');
return { installed: result.status === 0, log };
} catch (error) {
return {
installed: false,
log: `spawn error: ${error instanceof Error ? error.message : String(error)}`,
};
}
}
/**
* Ensure the spawned MCP server inherits a PATH that includes a valid Python installation
* WITH debugpy installed. This guards against environments (notably Windows CI) where
* Python is installed but not on PATH, or where newer Python versions lack debugpy.
*/
export function ensurePythonOnPath(env: Record<string, string>): void {
if (process.platform !== 'win32') {
return;
}
const pathDelimiter = ';';
const currentPath = env.PATH ?? env.Path ?? '';
const segments = currentPath ? currentPath.split(pathDelimiter).filter(Boolean) : [];
const normalized = new Set(segments.map((segment) => segment.toLowerCase()));
// Collect all candidate Python installations
const candidateRoots: string[] = [];
// Priority 1: PYTHONLOCATION (usually set by setup-python action with debugpy)
const envPythonLocation =
env.pythonLocation ??
env.PythonLocation ??
process.env.pythonLocation ??
process.env.PythonLocation;
if (envPythonLocation) {
candidateRoots.push(envPythonLocation);
}
// Priority 2: All Python versions in hostedtoolcache (sorted by version, oldest first)
const hostedToolCacheRoot = 'C:\\hostedtoolcache\\windows\\Python';
try {
if (fs.existsSync(hostedToolCacheRoot)) {
const versions = fs.readdirSync(hostedToolCacheRoot, { withFileTypes: true })
.filter(entry => entry.isDirectory())
.map(entry => ({
name: entry.name,
path: path.join(hostedToolCacheRoot, entry.name, 'x64')
}))
// Sort by version number (oldest first for stability)
.sort((a, b) => a.name.localeCompare(b.name, undefined, { numeric: true }));
for (const version of versions) {
candidateRoots.push(version.path);
}
}
} catch {
// Ignore discovery errors – absence simply means we fall back to existing PATH entries.
}
// Find the first Python with debugpy installed
let selectedRoot: string | null = null;
const diagnostics: string[] = [];
for (const root of candidateRoots) {
if (!root) {
continue;
}
const pythonExe = path.join(root, 'python.exe');
if (!fs.existsSync(pythonExe)) {
diagnostics.push(`${root}: python.exe not found`);
continue;
}
// Check for debugpy
const hasDebugpyInstalled = hasDebugpy(pythonExe);
diagnostics.push(`${root}: python.exe found, debugpy: ${hasDebugpyInstalled ? 'YES' : 'NO'}`);
if (hasDebugpyInstalled) {
selectedRoot = root;
break;
}
}
// If no Python with debugpy found, log diagnostics and use first available Python
if (!selectedRoot && candidateRoots.length > 0) {
console.warn('[env-utils] No Python with debugpy found. Diagnostics:');
diagnostics.forEach(d => console.warn(` ${d}`));
console.warn('[env-utils] Attempting to install debugpy for first available Python');
for (const root of candidateRoots) {
const pythonExe = path.join(root, 'python.exe');
if (!fs.existsSync(pythonExe)) {
continue;
}
const installResult = installDebugpy(pythonExe);
if (!installResult.installed) {
diagnostics.push(`${root}: debugpy install failed -> ${installResult.log.trim()}`);
continue;
}
diagnostics.push(`${root}: debugpy installed via pip`);
if (hasDebugpy(pythonExe)) {
selectedRoot = root;
break;
}
}
if (!selectedRoot) {
console.warn('[env-utils] debugpy installation attempts failed. Falling back to first Python found (tests may fail)');
for (const root of candidateRoots) {
const pythonExe = path.join(root, 'python.exe');
if (fs.existsSync(pythonExe)) {
selectedRoot = root;
break;
}
}
}
}
// Add the selected Python to PATH
let updated = false;
if (selectedRoot) {
const dirsToAdd = [selectedRoot, path.join(selectedRoot, 'Scripts')];
for (const dir of dirsToAdd) {
if (!fs.existsSync(dir)) {
continue;
}
const normalizedDir = dir.toLowerCase();
if (!normalized.has(normalizedDir)) {
segments.unshift(dir);
normalized.add(normalizedDir);
updated = true;
}
}
if (updated) {
console.log(`[env-utils] Added Python with debugpy to PATH: ${selectedRoot}`);
}
}
if (updated) {
const newPath = segments.join(pathDelimiter);
env.PATH = newPath;
env.Path = newPath;
}
}
