With the recent rework of conda build in #74, some packages cannot be found at install time (for symbiflow-arch-defs this happens during make all_conda).

In particular, the new yosys builds cannot be used within https://github.com/SymbiFlow/symbiflow-arch-defs as they cannot be fetched.

I suppose the issue lies in the new tagging mechanism, for which, if a tag is not compliant with a specific pattern, it gets set to v0.0.

The problem is that now, in conda channels there is a mix of two ways of tagging, probably causing the above mentioned errors: https://conda.anaconda.org/SymbiFlow/linux-64.
This happens for instance with Yosys, that, from a certain date, started to have a different tag convention.

There should be some more information in the README to understand how to correctly tag branches, so that there would be consistency across all packages (at least those under SymbiFlow control).