Failed to start devlopment server -- BindError: Unable to find a consistent port localhost

Question

Google-app-engine development server runs great yesterday, but when I try to start it today. It only shout out this Error. I tried use `lsof -i:8080` / `lsof -i:8000` to make sure these ports are not taken. I also tried use a --port arg to switch to another port. I even removed the gae folder and installed a new one. -- with no luck at all. Maybe there is a obvious solution but I can't see it. Here is the Oh-My-God trace stack.. ``` Traceback (most recent call last): File "/home/henry/software/google_appengine/dev_appserver.py", line 182, in _run_file(__file__, globals()) File "/home/henry/software/google_appengine/dev_appserver.py", line 178, in _run_file execfile(script_path, globals_) File "/home/henry/software/google_appengine/google/appengine/tools/devappserver2/devappserver2.py", line 689, in main() File "/home/henry/software/google_appengine/google/appengine/tools/devappserver2/devappserver2.py", line 682, in main dev_server.start(options) File "/home/henry/so…

Accepted Answer

This can be caused by multiple entries in your hosts file for 'localhost'.

For example in file `/etc/hosts`:

```
127.0.0.1 localhost
127.0.0.1 mymachinename localhost
```

if you delete all mappings but one for localhost, the problem will hopefully be resolved.

```
127.0.0.1 mymachinename localhost
```

This is a known issue and as far as I understand it will be corrected in a future release.

Failed to start devlopment server -- BindError: Unable to find a consistent port localhost

Solution

Problem