This is not a hard rule: under special cirmstances branches can be useful.
They should not however be considered "routine".
+For advice on commit messages see
+[here](https://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html),
+and [here](https://github.com/torvalds/subsurface-for-dirk/blob/master/README.md#contributing)).
+
## yosys
Follow the source code (git clone) instructions here, do **not** use