Bug#816101: petsc: FTBFS on mipsel - broken openmpi breaks petsc build

[Graham Inggs]

On 13/04/2016 12:59, Drew Parsons wrote:
> The failure happens during the test for mipsel-linux-gnu-real (the main
> build version).  It passes the first test using 1 MPI process.  It
> fails during the second test using 2 MPI processes. The test is ex19 in
> petsc-3.6.3.dfsg2/src/snes/examples/tutorials.

...

> This is the first test (1 process), which succeeds. The second test
> with two processes simply uses -n 2:
> $ PETSC_DIR=/home/dparsons/petsc/petsc-3.6.3.dfsg2 PETSC_ARCH=mipsel-linux-gnu-real LD_LIBRARY_PATH=:/home/dparsons/petsc/petsc-3.6.3.dfsg2/mipsel-linux-gnu-real/lib  mpirun -n 2 ./ex19 -da_refine 3 -pc_type mg -ksp_type fgmres
>
> This test doesn't "fail" as such, it just never completes. It must be
> caught in a deadlock.  I think the failure seen in the automated build
> is a timeout. Apparently the buildd halts the build after 5 hours.

This sounds a lot like the problem we have with powerpc, see bug 
#814183.  I think you may just have been very lucky in which powerpc 
buildds petsc has landed on lately.

In Ubuntu, I applied the following patch to get petsc to build on 
powerpc for the openmpi 1.10 transition.


--- a/src/snes/examples/tutorials/makefile
+++ b/src/snes/examples/tutorials/makefile
@@ -916,7 +916,7 @@
  	   else echo "Possible error running C/C++ 
src/snes/examples/tutorials/ex19 with 1 MPI process"; \
             echo "See 
http://www.mcs.anl.gov/petsc/documentation/faq.html";\
             cat ex19_1.tmp; fi; \
-	if [ "${MPIEXEC}" != "${PETSC_DIR}/bin/petsc-mpiexec.uni" ]; then \
+	if false; then \
             ${MPIEXEC} -n 2 ./ex19 -da_refine 3 -pc_type mg -ksp_type 
fgmres  > ex19_1.tmp 2>&1; \
  	   if (${DIFF} output/ex19_1.testout ex19_1.tmp > /dev/null 2>&1) then \
             echo "C/C++ example src/snes/examples/tutorials/ex19 run 
successfully with 2 MPI processes"; \