BEWARE: a problematic glibc made it to stable (F16)

[Simo Sorce]

On Wed, 2011-10-19 at 20:51 +0200, Jim Meyering wrote:
> I spent too many hours debugging this today, so feel obliged to warn
> about this.  Plus, I feel a little guilty for giving it positive
> karma initially.  Today's -1 was too late.
> 
> glibc-2.14.90-12.999, which has just made it to stable provokes a
> hard-to-diagnose (for me at least) problem.
> 
> While most things work, and it fixed two problems that affected me,
> it caused me some frustration:
> 
>     https//bugzilla.redhat.com/747377
> 
> TL;DR: while most things worked fine, and gcc even bootstrapped and
> passed most of "make check" (I did that when I was wondering if I had
> bad RAM), this version of glibc appears to make it so when you compile
> git from cloned sources, the resulting git program evokes double frees,
> arbitrary heap corruption, aborts, hangs, weird incomplete read errors,
> etc.  But only when you compile with -O2, not with -O1 or less.
> 
> Now, you might think that this is all git's fault, and maybe glibc is
> merely exposing it.  That may well be true.  Until we find the underlying
> cause we won't know for sure.  However, I was surprised to see that
> valgrind reported nothing, time after time, while glibc was obviously
> detecting heap corruption.
> 
> To recover an F16 system that works better, I ran this:
> 
>   yum downgrade glibc glibc-static glibc-devel glibc-common glibc-headers \
>     glibc-utils nscd

What did you downgrade to ?
AFAIK Several people had to downgrade from -11 because of nsswitch
issues ... seem glibc is not in good shape :-(

Simo.

-- 
Simo Sorce * Red Hat, Inc * New York