> If you upgrade a shared library to fix a problem, how do you know that the application has been tested against the fixed version?
Distro's like Debian solve that problem by not upgrading. The only things deemed worthy of "fixing" are security issues, and they are fixed by backporting the fix (only) to the existing shared library. Thus no API's (of any sort - even unofficial ones like screen scraping) are upgraded or changed, so no testing is necessary.
And thus:
> And no, your package manager won't know.
It doesn't have to know, because the package manager can assume all releases for Debian stable are backward compatible with all the packages in that release.
A lot of the noise you see on HN comes from people using distro's on their desktops. To them a distro is a collection of pre-packaged software with all the latest shinies, which they upgrade regularly. But Linux's desktop usage is 3%, whereas it server usage is claimed to be over 95% (which eclipses Windows Desktop share). Consequently distros are largely shaped not by the noisy desktop users, but by the requirements of sysadmin's. They need a platform that is guaranteed both stable and secure for years. To keep it stable, they must solve the problem you describe, and for the most part they have.
Distro's like Debian solve that problem by not upgrading. The only things deemed worthy of "fixing" are security issues, and they are fixed by backporting the fix (only) to the existing shared library. Thus no API's (of any sort - even unofficial ones like screen scraping) are upgraded or changed, so no testing is necessary.
And thus:
> And no, your package manager won't know.
It doesn't have to know, because the package manager can assume all releases for Debian stable are backward compatible with all the packages in that release.
A lot of the noise you see on HN comes from people using distro's on their desktops. To them a distro is a collection of pre-packaged software with all the latest shinies, which they upgrade regularly. But Linux's desktop usage is 3%, whereas it server usage is claimed to be over 95% (which eclipses Windows Desktop share). Consequently distros are largely shaped not by the noisy desktop users, but by the requirements of sysadmin's. They need a platform that is guaranteed both stable and secure for years. To keep it stable, they must solve the problem you describe, and for the most part they have.