Ok, I have been a couple of hours trying to find the solution to this:
AWS::S3::Errors::RequestTimeout: Your socket connection to the server was not read from or written to within the timeout period. Idle connections will be closed.
I was trying to run a rake:seed command in heroku
$ heroku run rake db:seed
And I got the above mentioned error once and again. It was strange because the behaviour was erratic, sometimes it would upload one file and break, and the next it could do the following.
Finally, I decided to investigate what was happening in the Amazon Bucket. So I opened the bucket and saw that there were some files. I then deleted all the folders with the contained files. And… magic! the error disapeared.
So what is my conclusion? there was something corrupt, or maybe you cannot run the seeds two times. Honestly, I have not tried a second time. It was already quite hard to get here. Next time I reset the database (it is in a staging app), I will find out if files in AWS S3 have to be deleted each time to avoid this conflict.
Hope this info is useful anyway! good luck