[Dune] MPI error of PAAMG test on ubuntu 11.10

[Patrick Leidenberger]

On 11/25/2011 01:11 PM, Jö Fahlke wrote:
> Am Thu, 24. Nov 2011, 07:40:28 +0100 schrieb Patrick Leidenberger:
>>> I don't use Ubuntu. But on Debian wheezy (testing) it works with g++
>>> 4.6.1 and openmpi 1.4.3
>>
>> Thanks, then it seems to be a special Ubuntu 11.10 bug. and not a
>> g++ 4.6.1 Problem.
>> Because that is not my only problem with with 11.10 I go back to
>> ubuntu 11.04, where everything was fine.
>
> A student of ours (Ansgar) discovered that Ubuntu appears to enable
> --as-needed in the linker.  One consequence is that libalugrid doesn't link
> against libmetis anymore (as seen with ldd).  We didn't yet check whether this
> actually has any ill consequences down the road.  Maybe this has something to
> do with it?
>
> You can see the compiler (and linker) defaults with "gcc -dumpspecs".
>
Hi Jö,

here is the output form my two systems:

ubuntu 11.04, gcc 4.5.2:
g++ -dumpspecs | grep as-needed
%{static|static-libgcc:-lgcc
-lgcc_eh}%{!static:%{!static-libgcc:%{!shared-libgcc:-lgcc --as-needed
-lgcc_s --no-as-needed}%{shared-libgcc:-lgcc_s%{!shared: -lgcc}}}}

ubuntu 11.10, gcc 4.6.1:
  g++ -dumpspecs | grep as-needed
%{!r:--build-id} --no-add-needed --as-needed %{!static:--eh-frame-hdr}
%{!m32:-m elf_x86_64} %{m32:-m elf_i386} --hash-style=gnu
%{shared:-shared}   %{!shared:     %{!static:
%{rdynamic:-export-dynamic}       %{m32:-dynamic-linker
%{muclibc:/lib/ld-uClibc.so.0;:%{mbionic:/system/bin/linker;:/lib/ld-linux.so.2}}} 

       %{!m32:-dynamic-linker
%{muclibc:/lib/ld64-uClibc.so.0;:%{mbionic:/system/bin/linker64;:/lib64/ld-linux-x86-64.so.2}}}} 

     %{static:-static}}
%{static|static-libgcc:-lgcc
-lgcc_eh}%{!static:%{!static-libgcc:%{!shared-libgcc:-lgcc --as-needed
-lgcc_s --no-as-needed}%{shared-libgcc:-lgcc_s%{!shared: -lgcc}}}}

Is there an easy way to disable as-needed to test the impact on the code?

Best regards

Patrick