Search alert: Google filetype search is broken. How to fix it?

I found some workarounds, not sure if they will hold

FIXED : bookmark this as fall back scenario.

The search community is on edge that Google may soon stop supporting filetype:pdf and other formats. It’s my favorite way of finding specialized documents and it would be a nightmare for me if Google really dumbs down their search engine.

I noticed the last four days that my favorite way of specifying documents…