Re: installing two versions of a user application

[Celejar <celejar@gmail.com>]

On Fri, 23 Apr 2021 18:07:02 +0100
Morgan Read <mstuff@read.org.nz> wrote:

> On 23/04/2021 5:40 pm, Celejar wrote:
> > I'll defer to those with a better understanding of the debian packaging
> > system internals, and it may depend on the details of the package, but
> > I'm pretty sure that there's no general way to direct dpkg to install a
> > package to a location other than the one specified by the package. If
> > the original packages were installable to separate directories, then it
> > should be possible to modify the debian packages to work that way as
> > well, but that's well above my pay grade.
> 
> Thanks Celejar, Just to be clear:
> v4 continues to install to /opt/master-pdf-editor-4;
> v5 continues to install to /opt/master-pdf-editor-5.
> But:
> When v4 is installed, /opt/master-pdf-editor-5 is deleted;
> When v5 is installed, /opt/master-pdf-editor-4 is deleted.
> Under the rpm based system, both /opt/master-pdf-editor-5 and
> /opt/master-pdf-editor-4 coexisted.  My memory is fading...  But, iirc,
> it may have been the case that whenever I upgraded v5 I had to reinstall
> v4 as the v5 install removed it.
> 
> The packages that Code Industry provides are clearly designed to get rid
> of v4, obviously because they now want people to buy those features.
> However, installing v4 over v5 never used to remove v5...
> 
> So, I wonder if alien might have done something in the transliteration
> of the v4 rpm to cause the v4 deb to remove other versions when it
> didn't as an rpm - or, is this just the mechanics of the apt system?
> 
> Many thanks.

See Stefan's answer - that's what I meant by modifying the debian
packages.

Celejar