If you’ve tried to do CI builds of Haskell projects using Travis/Gitlab/Jenkins, you would know the pain of long build times. Haskell builds are infamously slow, and if you require pandoc or gtk or other such large packages, your build may often even timeout on some of the free CIs. Caching makes this better, of course, but it is sometimes difficult to set up, and sometimes it is simply not available/possible.

This is especially irritating if your static blog is written in Hakyll, and is built with CIs (like this one). Hakyll requires pandoc, and most builds end up taking somewhere near an hour. This post will demonstrate a way to massively speed up time-consuming haskell builds like that in a neat way.