# Build Dialyzer PLTs on Travis CI

In a previous post, I wrote about how to easily get a prebuilt PLT for your Elixir builds on Travis. But what if that doesn’t work for you? What if you have special requirements that my prebuilt PLTs don’t meet?

## TL,DR;

You can fork my Travis PLT generator. You’ll just need an Amazon S3 bucket to store the resulting PLT files.

## How It Works

Since I’m not an expert at setting up Chef infrastructure, I knew that I wouldn’t be able to reliably get an identical virtual machine like the ones used by Travis in production. So, building the PLTs locally was not an option.

It seemed both easier and more reliable to have Travis build the PLTs itself. Since Travis is free for open source, I whipped up a simple repository and added a .travis.yml that:

1. Runs mix dialyzer from the dialyxir package.
2. Uses the Travis Artifacts script to upload the resulting file(s) to Amazon S3.

Since Travis allows running builds against multiple versions of Elixir and OTP, getting a PLT for each possible combination is a cinch:

language: elixir
elixir:
- 1.0.0
- 1.0.1
- 1.0.2
- 1.0.3
- 1.0.4
otp_release:
- 17.4
- 17.3
- 17.1
- 17.0

You’ll find more details in the README.