Frequently Asked Questions about Help

I'm having trouble with my configuration

• The IPP program <code>ppConfigDump</code> is useful for seeing your configuration as the code sees it. Run it as you would the binary that's giving you trouble, removing those command-line arguments that are specific to it, but keeping the general arguments:
  • <code>-recipe SOURCE TARGET</code>
  • <code>-D KEY VALUE</code>
  • <code>-Db KEY VALUE</code>
  • <code>-Di KEY VALUE</code>
  • <code>-Df KEY VALUE</code>
  • <code>-ipprc FILE</code>
  • <code>-camera CAMERA</code>
  • <code>-F OLD NEW</code>
• Also keep a representative input file (from which the camera type and format can be determined by the program; this then triggers the recipe overrides), and feed it to <code>ppConfigDump</code> with the <code>-file</code> flag.
• If you can't see anything wrong with the configuration, you can dump the user configuration (<code>ppConfigDump -file INPUT.fits -dump-user my_config.mdc</code>) and send it to someone who can run using your configuration by specifying it with the <code>-ipprc his_config.mdc</code> command-line argument to an IPP binary.
• Dumping the recipe (e.g., <code>ppConfigDump -file INPUT.fits -recipe PPIMAGE PPIMAGE_SOMETHING -dump-recipe PPIMAGE my_ppImage.mdc</code>) can be useful to see why some change isn't being seen by the program.

<pre> Pan-STARRS IPP configuration dumper Usage: ppConfigDump [-file INPUT.fits] [-dump-site FILE.mdc]

[-dump-camera FILE.mdc] [-dump-format FILE.mdc] [-dump-recipes FILE.mdc] [-dump-recipe RECIPE FILE.mdc]

FILE.mdc may be "-", in which case the file is written to stdout.

Optional arguments, with default values:

-file () FITS file to use for camera determination -dump-user () Filename for user configuration -dump-site () Filename for site configuration -dump-system () Filename for system configuration -dump-camera () Filename for camera configuration -dump-format () Filename for camera format -dump-recipes () Filename for recipes -dump-recipe () Name of recipe

() Filename

</pre>

I've got a segmentation violation or bus error

• You should never see these, so this is may be a major programming bug. They are caused by trying to read memory that shouldn't be read (segmentation violations are often caused by "dereferencing a <code>NULL</code> pointer").
• These can occur due to problems with dynamically linked libraries, e.g., if something changed in one library that didn't have a corresponding change in a dependent library, Bad Things can happen. To rule out this possibility, rebuild everything from scratch, and re-run.
• If the problem is still present, you should send the backtrace to the IPP developers.

How do I generate a backtrace?

• If you have a core dump (typically named something like <code>core.12345</code>, or just <code>core</code>), then do:

<pre> % gdb programName core.12345 (gdb) backtrace full </pre>

• You may not get a core dump if your resource limits are set to prohibit them. To turn on core dumps, do:

<pre> % limit coredumpsize unlimited # tcsh % ulimit -c ulimited # bash </pre>

• To produce a backtrace without a core dump, run the program under <code>gdb</code>, e.g.:

<pre> % gdb pxinject (gdb) run -newExp -tmp_exp_name simtest. 005.003 -tmp_inst /Users/tgrav/Work/Software/IPP/ipp-2.6.1-darwin/ default.darwin/share/ippconfig/simtest/camera.config -tmp_telescope / Users/tgrav/Work/Software/IPP/ipp-2.6.1-darwin/default.darwin/share/ ippconfig/simtest/camera.config -workdir /Users/tgrav/Work/ Observations/IPP/SIM/work -dvodb /Users/tgrav/Work/Observations/IPP/ SIM/DVO -tess_id /Users/tgrav/Work/Observations/IPP/SIM/TESS -label wait -dbname ippTest001 -trace pastro 10 ... Bus error (gdb) backtrace full </pre>