Re: Discussion about why GNU/Linux system upgrades cause old programs to break

"Dr. Arne Babenhauserheide" <[email protected]> Tue, 01 Sep 2026 13:59:38 +0200

Newsgroups	gmane.emacs.devel
Message-ID	<[email protected]>

Arsen Arsenović <[email protected]> writes:

> Richard Stallman <[email protected]> writes:
>
>> But as long as the user keeps running it on the same 32-bit platform,
>> which is quite likely to happen, it is not a bug in a concrete,
>> practical sense.  On that same 32-bit platform, the program would
>> never fail, except artificially if a newer GCC version refuses to
>> compile it.
>
> It is only possible to expect a bug remaining "abstract" if you never
> change any piece of the system the bug is "abstract" in.

Yes. And by changing the compiler to fail the compile in a situation in
which the program previously worked (where the bug was abstract), you
add a condition that breaks a working program.

Practical example where such bites:

- You have to update a library because it has a critical vulnerability
- The new library version requires a rebuild (I remember when libpng
  did) and uses new language features, so you have to update the compiler
- The new compiler version errors out when compiling your program

Now you have to patch your program instead of quickly updating the
library and recompiling. If the sysadmins do the update, they may even
have to call in someone from the dev-team to check the compiler error.
This can (greatly) increase the time window in which your system is
vulnerable (or offline, if you’re more careful).

Without the compiler change the re-compiled program would have worked
on this system without problems.

Best wishes,
Arne
-- 
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heißt politisch sein,
ohne es zu merken.
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