Check OS and npm concurrency ability

bootstrap.js

@@ -3,6 +3,7 @@
 const { execSync, spawn } = require('child_process');
 const { resolve } = require('path');
 const { existsSync } = require('fs');
+const { platform } = require('os');
 
 function shouldUseYarn() {
   try {
@@ -13,6 +14,17 @@ function shouldUseYarn() {
   }
 }
 
+function shouldUseNpmConcurrently() {
+  try {
+    const versionString = execSync('npm --version');
+    const m = /^(\d+)[.]/.exec(versionString);
+    // NPM >= 5 support concurrent installs
+    return Number(m[1]) >= 5;
+  } catch (e) {
+    return false;
+  }
+}
+
 const yarn = shouldUseYarn();
 const lerna = resolve(__dirname, 'node_modules', '.bin', 'lerna');
 if (!existsSync(lerna)) {
@@ -28,11 +40,21 @@ if (!existsSync(lerna)) {
 
 let child;
 if (yarn) {
-  child = spawn(lerna, ['bootstrap', '--npm-client=yarn'], {
+  // Yarn does not support concurrency
+  child = spawn(lerna, ['bootstrap', '--npm-client=yarn', '--concurrency=1'], {
     stdio: 'inherit',
   });
 } else {
-  child = spawn(lerna, ['bootstrap'], { stdio: 'inherit' });
+  let args = ['bootstrap'];
+  if (
+    // The Window's filesystem does not handle concurrency well
+    platform() === 'win32' ||
+    // Only certain npm versions support concurrency
+    !shouldUseNpmConcurrently()
+  ) {
+    args.push('--concurrency=1');
+  }
+  child = spawn(lerna, args, { stdio: 'inherit' });
 }
 
 child.on('close', code => process.exit(code));