Specific package updates on Raspberry Pi/Raspbian

The Raspbian package repos are, in my experience, extremely slow with updates. Ninja pre-dates version one, Python3 is still stuck on 3.5.2, and a lot of other packages are outdated. Installing from source isn't always easy, because they get new dependencies, and suddenly you have accidentally missing packages and compiling fails. So here's a list of some install guides for various tools. Note This is currently targeting a version of Raspbian that doesn't support 64 bit.