dev tag option is being removed from Docker images.
There’s been a fair amount of confusion around pulling Docker images with
dev tags–people expecting to pull the latest stable build and instead pulling the latest unstable build and then getting confused.
If you need the latest unstable build, you can get the compiled binary from the Developer Install section at http://www.mattermost.org/download/
If you’re developing the best is to pull from GitHub and do
make test on your dev machine.
While we realize that this could be inconvenient for people wanting to check out the freshest release, this was the most straight forward solution to address the poor experience some community members were having pulling the wrong Docker image.