diff --git a/bin/firebase b/bin/firebase
index 700b1d38..f61bce69 100755
--- a/bin/firebase
+++ b/bin/firebase
@@ -17,6 +17,7 @@ var configstore = require('../lib/configstore');
 var _ = require('lodash');
 var args = process.argv.slice(2);
 var handlePreviewToggles = require('../lib/handlePreviewToggles');
+var utils = require('../lib/utils');
 var cmd;
 
 var logFilename = path.join(process.cwd(), '/firebase-debug.log');
@@ -44,11 +45,14 @@ if (_.includes(args, '--debug')) {
 }
 
 logger.debug(_.repeat('-', 70));
-logger.debug('Command:     ', process.argv.join(' '));
-logger.debug('CLI Version: ', pkg.version);
-logger.debug('Platform:    ', process.platform);
-logger.debug('Node Version:', process.version);
-logger.debug('Time:        ', new Date().toString());
+logger.debug('Command:      ', process.argv.join(' '));
+logger.debug('CLI Version:  ', pkg.version);
+logger.debug('Platform:     ', process.platform);
+logger.debug('Node Version: ', process.version);
+logger.debug('Time:         ', new Date().toString());
+if (utils.envOverrides.length) {
+  logger.debug('Env Overrides:', utils.envOverrides.join(', '));
+}
 logger.debug(_.repeat('-', 70));
 logger.debug();
 
diff --git a/lib/auth.js b/lib/auth.js
index b8edca04..27f40b40 100644
--- a/lib/auth.js
+++ b/lib/auth.js
@@ -72,13 +72,15 @@ var _getTokensFromAuthorizationCode = function(code, callbackUrl) {
     }
   }).then(function(res) {
     if (!_.has(res, 'body.access_token') && !_.has(res, 'body.refresh_token')) {
+      logger.debug('Token Fetch Error:', res.statusCode, res.body);
       throw INVALID_CREDENTIAL_ERROR;
     }
     lastAccessToken = _.assign({
       expires_at: Date.now() + res.body.expires_in * 1000
     }, res.body);
     return lastAccessToken;
-  }, function() {
+  }, function(err) {
+    logger.debug('Token Fetch Error:', err.stack);
     throw INVALID_CREDENTIAL_ERROR;
   });
 };
diff --git a/lib/utils.js b/lib/utils.js
index 859f9b97..3ba752ce 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -11,6 +11,8 @@ var logger = require('./logger');
 
 var isWindows = process.platform === 'win32';
 
+var ENV_OVERRIDES = [];
+
 module.exports = {
   /**
    * Create a Firebase Console URL for the specified path and project.
@@ -49,6 +51,7 @@ module.exports = {
    */
   envOverride: function(envname, value, coerce) {
     if (process.env[envname] && process.env[envname].length) {
+      ENV_OVERRIDES.push(envname);
       if (coerce) {
         try {
           return coerce(process.env[envname], value);
@@ -60,6 +63,10 @@ module.exports = {
     }
     return value;
   },
+  /**
+   * A list of environment variable overrides that have been applied.
+   */
+  envOverrides: ENV_OVERRIDES,
 
   /**
    * Add a subdomain to the specified HTTP origin.