# Needed to set OMPI\_ARGV unused value to load PETSc **URL:** \ **Category:** General Discussion\ **Created:** [January 22, 2023, 2:42pm UTC](https://community.freefem.org/t/needed-to-set-ompi-argv-unused-value-to-load-petsc/2239 "2023-01-22T14:42:09Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![marchywka](https://avatars.discourse-cdn.com/v4/letter/m/ee59a6/32.png) [@marchywka](https://community.freefem.org/u/marchywka)\ **Post date:** [January 22, 2023, 2:42pm UTC](https://community.freefem.org/t/needed-to-set-ompi-argv-unused-value-to-load-petsc/2239/1 "2023-01-22T14:42:09Z")
After about a week of playing around I had to look at the MIP initialization. It seems that the arg list is pass to PETSc and then to MPI which eventually passes arg[1] to someone expecting a null terminated parameter list ( argc no longer is in the signature lol). Is this a well known or documented issue some where? From the error message it looked like a linking problem so I cyclted thorugh a bunch of mpi libs and other junk … I had to disasemble the code to find it … … ``` 8 : //load "PETSc" 9 : load "PETSc-complex" (load: dlopen /home/ubuntu/dev/freefem/install/lib/ff++/4.12/lib/mpi/PETSc-complex.so 0x15500c0) PETSc (St7complexIdE) ``` Program received signal SIGSEGV, Segmentation fault. strlen () at …/sysdeps/x86\_64/strlen.S:106 106 …/sysdeps/x86\_64/strlen.S: No such file or directory. (gdb) bt #0 strlen () at …/sysdeps/x86\_64/strlen.S:106 #1 0x00007ffff1ff3295 in opal\_argv\_join (argv=0x155a178, delimiter=32) at argv.c:297 #2 0x00007ffff273ca50 in ompi\_mpi\_init (argc=2, argv=0x155a170, requested=1, provided=0x7fffffffb21c, reinit\_ok=false) at runtime/ompi\_mpi\_init.c:505 #3 0x00007ffff2697bab in PMPI\_Init\_thread (argc=0x7fffffffb4b4, argv=0x7fffffffb4b8, required=1, provided=0x7fffffffb21c) at pinit\_thread.c:67 #4 0x00007fffeecc2dee in PetscInitialize (argc=0x7fffffffb4b4, args=0x7fffffffb4b8, file=0x0, help=0x7ffff08b7dc7 “”) at /home/ubuntu/dev/freefem/FreeFem-sources-master/3rdparty/ff-petsc/petsc-3.18.2/src/sys/objects/pinit.c:1244 #5 0x00007fffeecc3075 in PetscInitialize (argc=argc@entry=0x7fffffffb4b4, args=args@entry=0x7fffffffb4b8, file=file@entry=0x0, help=help@entry=0x7ffff08b7dc7 “”) at /home/ubuntu/dev/freefem/FreeFem-sources-master/3rdparty/ff-petsc/petsc-3.18.2/src/sys/objects/pinit.c:1269 #6 0x00007ffff084958d in Init\_PETSc () at PETSc-code.hpp:5475 #7 0x0000000000cee00b in call (a=…) at InitFunct.cpp:51 #8 0x0000000000cee7cc in std::for\_each\, std::pair\&, std::pair\_\>, void (_)(std::pair\ const&)\> (\_\_f=, \_\_last=…, \_\_first=…) at /usr/include/c++/5/bits/stl\_algo.h:3767 #9 callInitsFunct () at InitFunct.cpp:67 #10 0x0000000000cfa381 in load (ss=“PETSc-complex”) at load.cpp:104 #11 0x00000000008d5473 in lgparse () at lg.ypp:582 #12 0x00000000008d7bca in Compile () at lg.ypp:853 #13 0x00000000008d85f4 in mainff (argc=2, argv=0x7fffffffd1b8) at lg.ypp:1027 #14 0x00007ffff5599840 in \_\_libc\_start\_main ( main=0x8c1470 \, argc=2, argv=0x7fffffffd1b8, init=, fini=, rtld\_fini=, stack\_end=0x7fffffffd1a8) at …/csu/libc-start.c:291 #15 0x00000000008c51f9 in \_start () (gdb) ---
**Author:** ![marchywka](https://avatars.discourse-cdn.com/v4/letter/m/ee59a6/32.png) [@marchywka](https://community.freefem.org/u/marchywka)\ **Post date:** [January 22, 2023, 3:55pm UTC](https://community.freefem.org/t/needed-to-set-ompi-argv-unused-value-to-load-petsc/2239/2 "2023-01-22T15:55:28Z")
and then at the end, it seems to be waiting for some kind of close. Is this a MPI configuration issue? I would have thought FreeFem would tell these things to stop at the end. times: compile 0.065244s, execution 0.838418s, mpirank:0 ^C Thread 1 “FreeFem++” received signal SIGINT, Interrupt. 0x00007ffff55e8198 in \_IO\_new\_proc\_close (fp=0x147e980) at iopopen.c:339 339 iopopen.c: No such file or directory. (gdb) bt #0 0x00007ffff55e8198 in \_IO\_new\_proc\_close (fp=0x147e980) at iopopen.c:339 #1 0x00007ffff55f2970 in \_IO\_new\_file\_close\_it (fp=fp@entry=0x147e980) at fileops.c:172 #2 0x00007ffff55e63ff in \_IO\_new\_fclose (fp=0x147e980) at iofclose.c:58 #3 0x00000000008d30a7 in lgparse () at lg.ypp:387 #4 0x00000000008d7bca in Compile () at lg.ypp:853 #5 0x00000000008d85f4 in mainff (argc=2, argv=0x7fffffffd178) at lg.ypp:1027 #6 0x00007ffff5599840 in \_\_libc\_start\_main ( main=0x8c1470 \, argc=2, argv=0x7fffffffd178, init=, fini=, rtld\_fini=, stack\_end=0x7fffffffd168) at …/csu/libc-start.c:291 #7 0x00000000008c51f9 in \_start () (gdb) info threads Id Target Id Frame - 1 Thread 0x7ffff7fc0840 (LWP 17916) “FreeFem++” 0x00007ffff55e8198 in \_IO\_new\_proc\_close (fp=0x147e980) at iopopen.c:339 2 Thread 0x7fffeb92e700 (LWP 17929) “FreeFem++” 0x00007ffff567484d in poll () at …/sysdeps/unix/syscall-template.S:84 3 Thread 0x7fffe3fff700 (LWP 17930) “FreeFem++” 0x00007ffff5680b13 in epoll\_wait () at …/sysdeps/unix/syscall-template.S:84 (gdb) thread 2 [Switching to thread 2 (Thread 0x7fffeb92e700 (LWP 17929))] #0 0x00007ffff567484d in poll () at …/sysdeps/unix/syscall-template.S:84 84 …/sysdeps/unix/syscall-template.S: No such file or directory. (gdb) bt #0 0x00007ffff567484d in poll () at …/sysdeps/unix/syscall-template.S:84 #1 0x00007ffff20208f8 in poll (\_\_timeout=, \_\_nfds=1, \_\_fds=0x7fffe40008c0) at /usr/include/x86\_64-linux-gnu/bits/poll2.h:46 #2 poll\_dispatch (base=0x15ce930, tv=) at poll.c:165 #3 0x00007ffff201703f in opal\_libevent2022\_event\_base\_loop (base=0x15ce930, flags=1) at event.c:1630 #4 0x00007ffff1fae9f0 in progress\_engine (obj=0x15ce8e8) at runtime/opal\_progress\_threads.c:105 #5 0x00007ffff5ee26ba in start\_thread (arg=0x7fffeb92e700) at pthread\_create.c:333 #6 0x00007ffff568051d in clone () at …/sysdeps/unix/sysv/linux/x86\_64/clone.S:109 (gdb) thread 3 [Switching to thread 3 (Thread 0x7fffe3fff700 (LWP 17930))] #0 0x00007ffff5680b13 in epoll\_wait () at …/sysdeps/unix/syscall-template.S:84 84 …/sysdeps/unix/syscall-template.S: No such file or directory. (gdb) bt #0 0x00007ffff5680b13 in epoll\_wait () at …/sysdeps/unix/syscall-template.S:84 #1 0x00007ffff2013c78 in epoll\_dispatch (base=0x15f45c0, tv=) at epoll.c:407 #2 0x00007ffff201703f in opal\_libevent2022\_event\_base\_loop (base=0x15f45c0, flags=1) at event.c:1630 #3 0x00007fffeae6b803 in progress\_engine (obj=0x15f44c8) at runtime/pmix\_progress\_threads.c:232 #4 0x00007ffff5ee26ba in start\_thread (arg=0x7fffe3fff700) at pthread\_create.c:333 #5 0x00007ffff568051d in clone () at …/sysdeps/unix/sysv/linux/x86\_64/clone.S:109 (gdb) ---
**Author:** ![prj](https://avatars.discourse-cdn.com/v4/letter/p/ecae2f/32.png) [@prj](https://community.freefem.org/u/prj)\ **Post date:** [January 22, 2023, 4:57pm UTC](https://community.freefem.org/t/needed-to-set-ompi-argv-unused-value-to-load-petsc/2239/3 "2023-01-22T16:57:48Z")
It seems you are using `FreeFem++`, you need to use `FreeFem++-mpi`. ---
**Author:** ![marchywka](https://avatars.discourse-cdn.com/v4/letter/m/ee59a6/32.png) [@marchywka](https://community.freefem.org/u/marchywka)\ **Post date:** [January 22, 2023, 5:40pm UTC](https://community.freefem.org/t/needed-to-set-ompi-argv-unused-value-to-load-petsc/2239/4 "2023-01-22T17:40:47Z")
Thanks. Actually I forgot “mpirun” and did not have the current openmpi on the path either 🙂