Re: 2.4 / 2.5 compatibility?

[David Morris <lists at morris-clan dot net>]

On Thu, Jun 25, 2009 at 15:41, Mike Frysinger<vapier@gentoo.org> wrote:
> On Thursday 25 June 2009 17:20:47 David Morris wrote:
>> On Thu, Jun 25, 2009 at 15:15, Mike Frysinger wrote:
>> > On Thursday 25 June 2009 16:11:34 David Morris wrote:
>> >> I'm working on a project to get a large suite of software compile on
>> >> SuSE 10 (glibc 2.4) running on RedHat 5.3 (glibc 2.5). ?Recompiling
>> >> the software must be avoided if at all possible.
>> >>
>> >> The software seems to run with no problems, though we have only tested
>> >> a tiny fraction of the functionality. ?However, I (and others I have
>> >> talked to) have the impression that running with a different version
>> >> of glibc than software was compiled against is a "Bad Thing (tm)".
>> >>
>> >> Anyone know if there are any problems we can expect? ?Or am I mistaken
>> >> that there is a glibc version compatibility problem?
>> >
>> > your understanding isnt 100% complete, but it's fairly close. ?building
>> > code against one version of glibc and then attempting to use it under an
>> > *older* glibc is not going to work (well, it might accidentally work, but
>> > it is absolutely not supported). ?going the opposite way however --
>> > building code against one version and using it under a *newer* version --
>> > is absolutely supported and should always work. ?if it doesnt work, then
>> > it's a bug and you should report it. ?it might be that said bug has
>> > already been fixed in even newer versions of glibc, in which case do not
>> > expect anything older to be fixed. ?HTH.
>> > -mike
>>
>> Thank you for the clarification Mike! ?I (and a few others) were
>> apparently led astray by second-hand horror stories....which I'm
>> guessing based on the above, were going the reverse direction.
>
> i dont know how far back you need to go, but this is why we keep around a
> Debian install running etch "oldstable" ... it has glibc-2.3.6 installed. ?if
> we need binary packages for Linux, we build it up on that machine. ?havent had
> any complaints yet (ignoring the people who run on even older systems like
> glibc-2.2.5, but they're fairly rare nowadays).
> -mike
>

Good idea, I'll have to remember that.  Luckily that isn't an issue
for this project (other than to be certain its compiled on the correct
system!) as this is essentially a network appliance.

--David