On MongoDB failures print 20 lines of stderr and print a special error if mongod failed to start due to incompatible version of glibc.

Catch stderr before 'exit' signal

Try to give a good error message on outdated glibc/libstdc++.

Simplify error reporting to two lines.

Print only last 20 lines of stderr.

Slightly better error message.

tools/mongo_runner.js

@@ -172,7 +172,16 @@ exports.launch_mongo = function (app_dir, port, launch_callback, on_exit_callbac
       callback && callback(err);
     };
 
-    proc.on('exit', on_exit_callback);
+    var stderrOutput = '';
+
+    proc.stderr.setEncoding('utf8');
+    proc.stderr.on('data', function (data) {
+      stderrOutput += data;
+    });
+
+    proc.on('exit', function (code, signal) {
+      on_exit_callback(code, signal, stderrOutput);
+    });
 
     proc.stdout.setEncoding('utf8');
     proc.stdout.on('data', function (data) {

tools/run.js

@@ -628,11 +628,15 @@ exports.run = function (context, options) {
         }
         restartServer();
       },
-      function (code, signal) { // On Mongo dead
+      function (code, signal, stderr) { // On Mongo dead
         if (Status.shuttingDown) {
           return;
         }
-        console.log("Unexpected mongo exit code " + code + ". Restarting.");
+
+        // Print only last 20 lines of stderr.
+        stderr = stderr.split('\n').slice(-20).join('\n');
+
+        console.log(stderr + "Unexpected mongo exit code " + code + ". Restarting.\n");
 
         // if mongo dies 3 times with less than 5 seconds between each,
         // declare it failed and die.
@@ -645,6 +649,11 @@ exports.run = function (context, options) {
           if (explanation === mongoExitCodes.EXIT_NET_ERROR)
             console.log("\nCheck for other processes listening on port " + mongoPort +
                         "\nor other meteors running in the same project.");
+          if (!explanation && /GLIBC/i.test(stderr))
+            console.log("\nLooks like you are trying to run Meteor on old Linux " +
+                        "distribution. Meteor only supports Linux with glibc " +
+                        "version 2.9 and above. Try upgrading your distribution " +
+                        "to the latest version.");
           process.exit(1);
         }
         if (mongoErrorTimer)