FWIW:
$ apt-cache policy linux-headers-generic linux-headers-generic: Installed: 4.15.0.22.23 Candidate: 4.15.0.22.23 Version table: *** 4.15.0.22.23 500 500 http://us.archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages 500 http://security.ubuntu.com/ubuntu bionic-security/main amd64 Packages 100 /var/lib/dpkg/status 4.15.0.20.23 500 500 http://us.archive.ubuntu.com/ubuntu bionic/main amd64 Packages $
FWIW:
$ apt-cache policy linux-headers- generic generic: us.archive. ubuntu. com/ubuntu bionic-updates/main amd64 Packages security. ubuntu. com/ubuntu bionic- security/ main amd64 Packages dpkg/status us.archive. ubuntu. com/ubuntu bionic/main amd64 Packages
linux-headers-
Installed: 4.15.0.22.23
Candidate: 4.15.0.22.23
Version table:
*** 4.15.0.22.23 500
500 http://
500 http://
100 /var/lib/
4.15.0.20.23 500
500 http://
$