Subject: bug#54033: Calibre's ebook-viewer only shows white-on-white or dark-on-dark.

From: Jacob MacDonald <[email-masked]>
Date: Thu, 17 Feb 2022 01:05:09 -0600

Calibre's main window is unaffected, but it's impossible to read any
EPUBs in the viewer. The text in both the book and the settings is
affected. Images show up.

I don't remember if I noticed this before or after the bit QtWebKit
removal a few weeks ago. It would be a strange root cause but is the
only thing I can see that makes sense temporally.