xsel does not exit

[Jarno Suni]

Examples:

echo foo | xsel -i

cat bar | xsel -i

xsel process does not terminate, but is in interruptible sleep.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xsel 1.2.0+git9bfc13d.20180109-3
ProcVersionSignature: Ubuntu 5.4.0-54.60-generic 5.4.65
Uname: Linux 5.4.0-54-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.13
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: XFCE
Date: Sun Nov 29 13:10:15 2020
InstallationDate: Installed on 2019-12-05 (359 days ago)
InstallationMedia: Xubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017)
SourcePackage: xsel
UpgradeStatus: Upgraded to focal on 2020-07-10 (142 days ago)