So I found this out today..
wget something in default mode (no flags) in a terminal, you get progress.
But that progress is actually STDERR
Which means that if you do something like wget in the middle of a Dockerfile you get great big bright red obnoxious errors that you didn’t expect.
To solve this, use
wget -q where you can. It mightn’t be the most helpful when debugging, but it’ll nix those annoying red blobs that make you think “GOSH WHAT DID I DO WRONG THIS TIME?”
 *I’m currently in a love hate relationship with docker. I love it’s caching for iterative design, but I hate it’s complex overloaded CLI structure and things like the subject of this post.