Signal 18 (CONT) caught by ps (procps-ng version 3.3.9).

[ole.tange]

#1055551 shows the problem for zsh, but the problem can also be provoked in bash:

1. Start 30000 processes (e.g. sleep) This is needed to slow down `ps`.
2. Install GNU Parallel 20140815alpha (which uses `ps`)
3. Run: seq 100 | parallel -j0 parallel -j3 --semaphore sleep .{}\\\;echo {} \\\>\\\> /tmp/log
4. When `pstree` shows that parallel has started some ps-processes: CTRL-Z
5. Wait a few seconds
6. fg

Output 100 times:
Signal 18 (CONT) caught by ps (procps-ng version 3.3.9).
ps:display.c:66: please report this bug

It does not seem to cause a problem, so low priority.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: procps 1:3.3.9-1ubuntu2
ProcVersionSignature: Ubuntu 3.13.0-32.57-lowlatency 3.13.11.4
Uname: Linux 3.13.0-32-lowlatency x86_64
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
Date: Wed Aug 20 17:06:13 2014
InstallationDate: Installed on 2013-10-10 (313 days ago)
InstallationMedia: Linux Mint 15 "Olivia" - Release amd64 (20130520)
ProcEnviron:
 LANGUAGE=
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: procps
UpgradeStatus: No upgrade log present (probably fresh install)
mtime.conffile..etc.sysctl.conf: 2013-10-19T18:55:19.632103

[ole.tange (n-launchpad-net-tange-dk)]

Seems not to exist on Ubuntu 18.04.