I have been troubled by this bug for (perhaps) months.
It is easy enough to reproduce, and I can figure out how to stop things while leaving cups functional.
I am running a current sid system
ii cups-daemon 2.2.1-3 amd64 Common UNIX Printing System(tm) - daemon
I do not pretend to understand what is going on, but there seems to be a conflict between the starting of cups via the /etc/init.d/cups script (provided by cups-daemon) and its access through systemd.
In particular, upon reboot I will find cupsd driving a CPU at 100% polling constantly for PPD data as described in the original post.
Stopping the init.d script produces
/home/trs# /etc/init.d/cups stop
[....] Stopping cups (via systemctl): cups.serviceWarning: Stopping cups.service, but it can still be activated by:
cups.path
cups.socket
. ok
And at this point everything is fine. There are valid PPDs and printer descriptions for all network printers, and printing works.
I have not tried deactivating the init.d script, since I reboot infrequently and I have this temporary fix.
If there is more information that I can provide to assist, please let me know.
TRS
--
Thomas R. Shemanske
Department of Mathematics, Dartmouth College
6188 Kemeny Hall, 27 N Main St
Hanover, NH 03755-3551
603-646-3179