I've been using Sigil for a few years now. My main publication is a travel guide that refers to a thousand URLs. I've been testing them with this plugin for some time, however it fails at checking some without giving much info on what was going on or even stalling on a few that I had to remove (while they work perfectly fine in a web browser).
Python is not my preferred language, but, uh, well, I gave it a try and came to this new version that should hopefully give you more details on errors like :
- 301 - moved permanently : probably an old URL that you should change for the new one
- 302 - Found (aka moved temporarily) : may also need a revision
- 404 - Not found : broken link
- SSL error - Invalid certificate on server's side : probably not maintained
- getaddrinfo errors : site not found, probably a dead site
I also dropped support for Python 2, since it reached end of life some time ago.