Bug 411103

Summary: KDE Neon apt-get ruby script fails if system ruby is removed
Product: [KDE Neon] neon Reporter: Lasha Abulashvili <labulashvili>
Component: generalAssignee: Neon Bugs <neon-bugs-null>
Status: RESOLVED NOT A BUG    
Severity: normal CC: jr, neon-bugs-null, sitter
Priority: NOR    
Version First Reported In: unspecified   
Target Milestone: ---   
Platform: Neon   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Lasha Abulashvili 2019-08-20 14:36:55 UTC 
SUMMARY
Let's imagine a scenario where I install RVM to manage my ruby installations and I want to remove system ruby because I know I won't be using it.

STEPS TO REPRODUCE
1. Remove system ruby 

OBSERVED RESULT
result of removing system ruby is that atp-get is broken and error message is very confusing.

EXPECTED RESULT
apt-get should continue to work with RVM ruby on report the installation steps to bring system ruby back.

SOFTWARE/OS VERSIONS
Will affect all KDE Neon versions that are using apt-get ruby script replacement

ADDITIONAL INFORMATION
I understand that apt-get is patched in order to let users know that they shouldn't use apt-get upgrade and that they should use pkcon update instead. This script should look for alternate ruby installations or report proper one-liner script to install ruby back, because as apt-get doesn't work, apt-get install ruby doesn't work either. The workaround is to use /usr/bin/apt-get, instead of /usr/sbin/apt-get (this one is a ruby script)
Comment 1 Harald Sitter 2019-08-20 14:51:27 UTC 
you'll want to install a fake deb to replace the ruby dependency

you're asking to break your dependency chain on account of the dependency only being a relocatable runtime dependency. deb has no solution for that.

it's like when I install my own Qt and want to remove the system Qt because now I don't need it but then apt wants to remove dragonplayer. same exact problem. there's nothing functionally preventing dragonplayer from working with my Qt build, deb doesn't know that I have my own Qt though
Comment 2 Lasha Abulashvili 2019-08-20 14:54:24 UTC 
At least a friendly notice would be necessary, because I spent an hour with ubuntu folks on IRC helping me to figure out why the terminal would randomly throw /etc/env ruby not found error. Some people may never figure it out and they may just remove KDE Neon for that reason :)