Gcc testsuite, LD_LIBRARY_PATH, and a new libgcc_s that is incompatible with the host libc

[Andrew Haley]

On 06/22/2012 03:27 PM, Ian Lance Taylor wrote:
> Andrew Haley <aph@redhat.com> writes:
> 
>> On 06/22/2012 11:35 AM, Simon Baldwin wrote:
>>> Firstly, has anyone else encountered this or otherwise given it any
>>> thought?  And secondly, any hints for practical fixes?
>>
>> What you effectively seem to be building is a cross-compiler from
>> x86-glibc-A to x86-glibc-B.  To run your tests, you want a machine
>> that's running x86-glibc-B.  I would have thought the best way to
>> achieve this would be to run the tests in a chroot that is your
>> sysroot.  That's what gcc is compiling for.
> 
> That does not address the problem, at least not in any straightforward
> way.  The problem is not running the tests, it's running the expect
> binary itself.  Due to the setting of LD_LIBRARY_PATH before starting
> expect, expect is picking up the newly built libgcc_s.so.  This fails in
> a rather obscure manner because expect is not actually linked against
> libgcc_s.so, but instead picks it up via the rather baroque way that
> glibc implements pthread_cancel.

Well, yes, I realize that.  My point is that you run expect on the host
machine, and treat the virtual machine in the sysroot as the target, just
as if you were cross-compiling.  Which, in fact, you are.

Andrew.