Long story short, printing on a chromebook is still fucked, and now the incompetent dickheads who write drivers for HP have made things worse. With time and effort, however, one can still repair the damage. Writing this up in case somebody finds it useful, and because I have little doubt I’ll be referring to it again in the near future.
First, the problem: printing from a chromebook to a local network printer no longer works. There is an extension that used to make this possible. If one reads the reviews, one will quickly notice the many, many one star reviews saying that it doesn’t work. In particular, it used to work, but after the March 20 update it completely unhelpfully and uselessly does nothing but say “Printing unsuccessful”. That was more than a month ago. The rockstar talent at HP is apparently on tour and too busy to fix this.
Here’s the insane workaround. First we need the old version of the extension. Obviously Google will never let us have it, but there’s an archive site. Here’s the previous print extension. Download that. Rename the file to zip. Create a new folder and extract the contents of the zip file. Rename the _metadata folder to not_metadata. Open the chrome extensions panel. Delete the old HP Print extension. Flip into developer mode. Add an unpacked extension. Add back the printer IP address and rejoice.
For bonus fun, talk your mom through this procedure over the phone.