Builds are failing with "memory exceeded" error

Suddenly since today all our builds are failing with the error

Your build has exceeded the memory limit of 8G on 1 container. The results of this build are likely invalid. We have taken a snapshot of the memory usage at the time, which you can find in a build artifact named memory-usage.txt. The RSS column in this file shows the amount of memory used by each process, measured in kilobytes.

The sum of the whole RSS column in the memory-usage.txt file is about 3GB though.

The last successful build was 7 days ago. I don’t see anything changed that might affect the memory usage since then.

We are still on Circle 1.0.

You can find the latest failed build at https://circleci.com/gh/ilovept/gymapp/3270.