Comment 6 for bug 1802958

Clarification to comment #5 :

- apt install ghostscript, upgrades only ghostscript and libgs9 but NOT libgs9-common :

jo@xenial-build:~$ dpkg -l | grep ghostscript
ii ghostscript 9.25~dfsg+1-0ubuntu0.16.04.1 amd64 interpreter for the PostScript language and for PDF
jo@xenial-build:~$ dpkg -l | grep libgs9
ii libgs9:amd64 9.25~dfsg+1-0ubuntu0.16.04.1 amd64 interpreter for the PostScript language and for PDF - Library
ii libgs9-common 9.25~dfsg+1-0ubuntu0.16.04.1 all interpreter for the PostScript language and for PDF - common files
jo@xenial-build:~$ sudo apt install ghostscript
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  libgs9
Suggested packages:
  ghostscript-x hpijs
The following packages will be upgraded:
  ghostscript libgs9
2 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.
Need to get 0 B/2,311 kB of archives.
After this operation, 2,048 B of additional disk space will be used.
Do you want to continue? [Y/n] Y
(Reading database ... 35659 files and directories currently installed.)
Preparing to unpack .../ghostscript_9.25~dfsg+1-0ubuntu0.16.04.2_amd64.deb ...
Unpacking ghostscript (9.25~dfsg+1-0ubuntu0.16.04.2) over (9.25~dfsg+1-0ubuntu0.16.04.1) ...
Preparing to unpack .../libgs9_9.25~dfsg+1-0ubuntu0.16.04.2_amd64.deb ...
Unpacking libgs9:amd64 (9.25~dfsg+1-0ubuntu0.16.04.2) over (9.25~dfsg+1-0ubuntu0.16.04.1) ...
Processing triggers for man-db (2.7.5-1) ...
Processing triggers for libc-bin (2.23-0ubuntu10) ...
Setting up libgs9:amd64 (9.25~dfsg+1-0ubuntu0.16.04.2) ...
Setting up ghostscript (9.25~dfsg+1-0ubuntu0.16.04.2) ...
Processing triggers for libc-bin (2.23-0ubuntu10) ...
jo@xenial-build:~$ dpkg -l | grep ghostscript
ii ghostscript 9.25~dfsg+1-0ubuntu0.16.04.2 amd64 interpreter for the PostScript language and for PDF
jo@xenial-build:~$ dpkg -l | grep libgs-9
jo@xenial-build:~$ dpkg -l | grep libgs9
ii libgs9:amd64 9.25~dfsg+1-0ubuntu0.16.04.2 amd64 interpreter for the PostScript language and for PDF - Library
ii libgs9-common 9.25~dfsg+1-0ubuntu0.16.04.1 all interpreter for the PostScript language and for PDF - common files

-After upgrade ghostscript from -proposed :

jo@xenial-build:~$ sudo apt-get install ghostscript/xenial-proposed
Reading package lists... Done
Building dependency tree
Reading state information... Done
Selected version '9.25~dfsg+1-0ubuntu0.16.04.3' (Ubuntu:16.04/xenial-proposed [amd64]) for 'ghostscript'
Selected version '9.25~dfsg+1-0ubuntu0.16.04.3' (Ubuntu:16.04/xenial-proposed [amd64]) for 'libgs9' because of 'ghostscript'
Selected version '9.25~dfsg+1-0ubuntu0.16.04.3' (Ubuntu:16.04/xenial-proposed [all]) for 'libgs9-common' because of 'libgs9'
The following additional packages will be installed:
  libgs9 libgs9-common
Suggested packages:
  ghostscript-x hpijs fonts-droid texlive-lang-cjk
The following packages will be upgraded:
  ghostscript libgs9 libgs9-common
3 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B/7,407 kB of archives.
After this operation, 10.2 kB of additional disk space will be used.
Do you want to continue? [Y/n] Y
(Reading database ... 35659 files and directories currently installed.)
Preparing to unpack .../libgs9-common_9.25~dfsg+1-0ubuntu0.16.04.3_all.deb ...
Unpacking libgs9-common (9.25~dfsg+1-0ubuntu0.16.04.3) over (9.25~dfsg+1-0ubuntu0.16.04.1) ...
Preparing to unpack .../ghostscript_9.25~dfsg+1-0ubuntu0.16.04.3_amd64.deb ...
Unpacking ghostscript (9.25~dfsg+1-0ubuntu0.16.04.3) over (9.25~dfsg+1-0ubuntu0.16.04.2) ...
Preparing to unpack .../libgs9_9.25~dfsg+1-0ubuntu0.16.04.3_amd64.deb ...
Unpacking libgs9:amd64 (9.25~dfsg+1-0ubuntu0.16.04.3) over (9.25~dfsg+1-0ubuntu0.16.04.2) ...
Processing triggers for man-db (2.7.5-1) ...
Processing triggers for libc-bin (2.23-0ubuntu10) ...
Setting up libgs9-common (9.25~dfsg+1-0ubuntu0.16.04.3) ...
Setting up libgs9:amd64 (9.25~dfsg+1-0ubuntu0.16.04.3) ...
Setting up ghostscript (9.25~dfsg+1-0ubuntu0.16.04.3) ...
Processing triggers for libc-bin (2.23-0ubuntu10) ...
jo@xenial-build:~$ dpkg -l | grep ghostscript
ii ghostscript 9.25~dfsg+1-0ubuntu0.16.04.3 amd64 interpreter for the PostScript language and for PDF
jo@xenial-build:~$ dpkg -l | grep libgs9
ii libgs9:amd64 9.25~dfsg+1-0ubuntu0.16.04.3 amd64 interpreter for the PostScript language and for PDF - Library
ii libgs9-common 9.25~dfsg+1-0ubuntu0.16.04.3 all interpreter for the PostScript language and for PDF - common files