I discovered a mistake in my own published workshop paper, how do I handle errata?
Mistakes happen. I would say that since it's a conference proceedings, therefore often the presented work is short of proofs, it's work in progress and it's very quickly baked, mistakes happen.

It is probably impossible to post errata to the paper. I would suggest the following steps:


If you put it on arXiv, upload a new corrected version.
If you put it on your personal webpage, add the errata there.
Make sure that once you sumbit it for journal publication, the mistake is correted.