Stop assets from being precompiled locally for loc

Question

This app is deployed on heroku and uses asset_sync gem with s3 to serve assets. I want to run my rails server in production locally to test out things before deployment to heroku. When I run rake assets:precompile My local machine uploads files to my s3 bucket (all works fine) but I also notice assets are precompiled in my local public folder.

Precompiling on S3 and locally seems redundant, sometimes I want the assets precompiled to just S3, other times I may want to run a local production server with assets from my public directory and not bother uploading / referencing S3.

So how would I configure my machine to stop assets from being precompiled locally?

I'm open to any ways to configure my system. Right now

I added several variables to my .bash_profile to store my AWS credentials.

export AWS_ACCESS_KEY_ID=xxx
export AWS_SECRET_ACCESS_KEY=yyy
export S3_BUCKET_NAME=my_bucket_name
export FOG_PROVIDER=AWS
export FOG_DIRECTORY=my_bucket_name

I've tried a rails environment/production.rb entry:

config.serve_static_assets = false

Thanks