This repo has submodules, so you have to clone it to build it - the source code archives in the releases page won't work. (This is a GitHub bug and there doesn't appear to be any way around it.)
To clone the repo:
git clone --recursive https://github.com/tom-seddon/b2.git
If you're reading this after already cloning it:
git submodule init
git submodule update
Regarding branches, master should always build, and shouldn't
contain anything outrageously half-baked - it's the branch used by the
CI servers to prepare releases.
wip/* is stuff that's being worked on.
Once you're all set up:
Instructions for building on Windows.
Instructions for building on macOS.
Instructions for building on Linux/macOS.
The submodules are referred to by https. Before cloning, you can use
git config --global url.ssh://git@github.com/.insteadOf https://github.com/ to have them cloned over SSH instead, if you have
a GitHub login.
Some info about the 3rd party 6502 tests that run as part of the full test set.
Some info: http://visual6502.org/wiki/index.php?title=6502TestPrograms
Everything you need to do this on Windows is included in the repo; for macOS and Linux, you'll need GNU make, and 64tass on the path.
Change to etc/testsuite-2.15 and run ..\..\bin\snmake (Windows) or
make (macOS/Linux). This generates bin files in
etc/testsuite-2.15/ascii-bin and listing files in
etc/testsuite-2.15/ascii-lst.
Original repo: https://github.com/Klaus2m5/6502_65C02_functional_tests
(I don't remember why this isn't a submodule...)
Change to etc/6502_65C02_functional_tests and run
..\..\bin\snmake. You get bin and listing files in
etc/6502_65C02_functional_tests.