But that's a policy decision - the dependencies should themselves be packages, because that's the only way to guarantee reliability.
The inability to install multiple versions is probably the only serious problem with the dpkg model. Even then we might argue that the dependent software should be fixed so that it's not so fussy about specific dependency versions.
Of course this is work for application as well as library developers, designing and keeping compatibility is hard. Most would rather build the new shiny, consequences be damned.
When I left that position, we were in the middle of an OpenShift (k8s) deployment, and one of the things motivating the change was the ability to more easily run separate versions of services for different customers if the need arose. Yes, this would put a lot more burden on us as the service provider, but it would also allow us to iterate faster while maintaining stability.
Sure, but this should be considered either a defect or something highlighted by a major version number jump.
Or maybe he agrees and fixes it and it's included in distributions 7 years later.
I've changed 5 jobs in 7 years (because of life circumstances) and I'm not even a job hopper... How is any commercial shop going to plan around 7 year time frames?
It's effectively part of insisting that it's properly Free software - if you can't maintain your own bugfixed fork, but have to keep going to an external organisation for their version, is it really Free?
Also can't install to separate disks.
But that raises the question: why are your file systems sensitive to disk drives? Use a layer (or more) of indirection through LVM and RAID so to make the drive placement opaque and robust.
A couple of systems I have at home have a 16GB primary disk, so it is useful to be able to put things on an external disk. I have yet to see any package manager that can actually handle that.
> Use a layer (or more) of indirection through LVM and RAID...
Yeah, that's a great idea, just introduce more complication and abstraction to make up for a shortcoming in how Linux developers think about applications.
Or, just have your programs be self contained in a single file or folder and put them wherever it makes sense.