Hello I am trying to debug a program using the switch '-on_error_attach_debugger' but the vendor/sysadmin built PETSc 3.2.00 is unable to start the debugger in xterm (see text below). But xterm is installed. What am I doing wrong? Btw the segfault happens during a call to MatMult but only with vendor/sysadmin supplied PETSc 3.2 with PGI and Intel compilers only and _not_ with CRAY or GNU compilers. I also dont get the segfault if I build PETSc 3.2-p7 myself with PGI/Intel compilers. Any ideas on how to diagnose the problem? Unfortunately I cannot seem to run valgrind on this particular machine. Thanks in advance. Tabrez --- stali@krakenpf1:~/meshes> which xterm /usr/bin/xterm stali@krakenpf1:~/meshes> aprun -n 1 ./defmod -f 2d_point_load_dyn_abc.inp -on_error_attach_debugger ... ... ... [0]PETSC ERROR: ------------------------------------------------------------------------ [0]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation, probably memory access out of range [0]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger [0]PETSC ERROR: or see http://www.mcs.anl.gov/petsc/petsc-as/documentation/faq.html#valgrind[0]PETSC ERROR: or try http://valgrind.org on GNU/linux and Apple Mac OS X to find memory corruption errors [0]PETSC ERROR: configure using --with-debugging=yes, recompile, link, and run [0]PETSC ERROR: to get more information on the crash. [0]PETSC ERROR: User provided function() line 0 in unknown directory unknown file [0]PETSC ERROR: PETSC: Attaching gdb to ./defmod of pid 32384 on display localhost:20.0 on machine nid10649 Unable to start debugger in xterm: No such file or directory aborting job: application called MPI_Abort(MPI_COMM_WORLD, 0) - process 0 _pmii_daemon(SIGCHLD): [NID 10649] [c23-3c0s6n1] [Mon Apr 2 13:06:48 2012] PE 0 exit signal Aborted Application 133198 exit codes: 134 Application 133198 resources: utime ~1s, stime ~0s