Following up on Is Ubuntu LTS binary compatible with Debian?
I know Ubuntu and Debian binary packages are incompatible more often than not. I know mixing packages from different sources is generally a bad idea, and people get warned against doing that all the time. So let's keep the discussion pure technical --
What exactly will introduce incompatibility for packages from different sources, when of course the dependencies are not the problem?
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Like the saying:
about binary compatibility (https://wiki.ubuntu.com/MarkShuttleworth#What_about_binary_compatibility_between_distributions.3F): Debian packages are likely built with different toolchain versions, so you may incur in troubles
Why different toolchain versions will give problem? Like
- I know how to pull the minimum set of packages from Debian sid into my Debian stable, and had been doing that all the time,
- I used to carry packages from older version of Ubuntu / Debian to their newer versions, or even
- copying a single executable from my Ubuntu / Debian to another distro, be it RedHat or even FreeBSD,
and never had problem before. So what exactly is causing the problem that people are saying?
Is it gcc or kernel version? Unlikely to me, as they get upgraded all the time throughout the lifespan of me using that release.
So it is the version of glibc? But it'll be backward compatible normally and most probably, right?
Quoting from the answer from my first link:
There really is no guarantee or even implication of cross-compatibility. Don't expect either the Debian or Ubuntu communities to give you much sympathy if things go wrong. In that event you're mostly on your own. As long as you're okay with that then feel free to give it a try.
So basically I see warning against the practice everywhere, but nobody give further technical explanation. Can anyone list the risks of doing so, those potential technical problems please?
That answer will help me, if I want/need to mixing packages from different sources, say Debian or Ubuntu, or within the same distro but different releases, (if the dependencies are not the problem), to choose the safest approach, to pull a PPA that I know for sure will never end up in Debian, into the Debian Bullseye that I'm currently using.