F#/Mono build is slow

I have project that uses Mono and .NETCore to build code as CI gate.
See https://travis-ci.org/fsprojects/fantomas.
However it takes forever to build my code as every single time it needs to download both Mono and .NETCore before running my code.

I’m interested in using Docker (this image works fine https://github.com/ninjarobot/docker-fsharp-mono-netcore) but I’m not sure how to proceed.

I basically want to pull the image and do a docker run. However if something goes wrong in the container will I have the same level of detail as something going wrong in my current setup?
And how would I set this up in my .travis-ci.yml?
I find the docs a bit confusing on that end.

Many thanks.

If you can do everything you need locally via docker, then it’s pretty easy to translate that to docker-in-travis. You need to add the docker service to your travis yaml, and then you can run any docker commands as part of your script. as far as logging, etc anything from standard out will appear in the docker logs, so I think you’ll be ok there. Detailed docs can be found at https://docs.travis-ci.com/user/docker/, and if you want to tag me on a github PR for detailed discussion I’m @baronfel over there

Thanks, I’ll try something out this week and perhaps ping you for a review.