Hide stderr git output during APM agent configuration

config/apm.js

@@ -42,19 +42,22 @@ const { join } = require('path');
 const { execSync } = require('child_process');
 const merge = require('lodash.merge');
 
-module.exports = merge({
-  active: false,
-  serverUrl: 'https://f1542b814f674090afd914960583265f.apm.us-central1.gcp.cloud.es.io:443',
-  // The secretToken below is intended to be hardcoded in this file even though
-  // it makes it public. This is not a security/privacy issue. Normally we'd
-  // instead disable the need for a secretToken in the APM Server config where
-  // the data is transmitted to, but due to how it's being hosted, it's easier,
-  // for now, to simply leave it in.
-  secretToken: 'R0Gjg46pE9K9wGestd',
-  globalLabels: {},
-  centralConfig: false,
-  logUncaughtExceptions: true
-}, devConfig());
+module.exports = merge(
+  {
+    active: false,
+    serverUrl: 'https://f1542b814f674090afd914960583265f.apm.us-central1.gcp.cloud.es.io:443',
+    // The secretToken below is intended to be hardcoded in this file even though
+    // it makes it public. This is not a security/privacy issue. Normally we'd
+    // instead disable the need for a secretToken in the APM Server config where
+    // the data is transmitted to, but due to how it's being hosted, it's easier,
+    // for now, to simply leave it in.
+    secretToken: 'R0Gjg46pE9K9wGestd',
+    globalLabels: {},
+    centralConfig: false,
+    logUncaughtExceptions: true,
+  },
+  devConfig()
+);
 
 const rev = gitRev();
 if (rev !== null) module.exports.globalLabels.git_rev = rev;
@@ -66,7 +69,10 @@ try {
 
 function gitRev() {
   try {
-    return execSync('git rev-parse --short HEAD', { encoding: 'utf-8' }).trim();
+    return execSync('git rev-parse --short HEAD', {
+      encoding: 'utf-8',
+      stdio: ['ignore', 'pipe', 'ignore'],
+    }).trim();
   } catch (e) {
     return null;
   }