Environmental variable coming back as literal braces I have my general config file set up as follows:

return array(
  'localhost' =&gt; array(
  'devMode' =&gt; true,
  'environmentVariables' =&gt; array(
    'baseUrl' =&gt; 'http://localhost:8888/path/to/site/'
  )
 );


Then, I have an asset source set up as follows:

File Base Path: assets/img/general/
URL: {baseUrl}assets/img/general/


The assets pulled within a template get this error: 

GET http://localhost:8888/path/to/site/%7BbaseUrl%7Dassets/img/headers/image.jpg 404 (Not Found)


I've used this format with several other sites before, and haven't had a problem. Does anyone have any suggestions?
Your config/general.php file code has some problem with it.

You're missing a closing ) for an array, which I suspect is a typo, but the issue to your real problem is probably the fact you're missing the required '*' key for multi-environment configs to work properly.

See the first warning note on this page: https://craftcms.com/docs/multi-environment-configs