ubuntu-bug does nothing for kernel thread PIDs

kacpid is not a "real" program, it's a kernel thread. However, ubuntu-bug should give a proper error message for nonexisting PIDs.

The behaviour for nonexisting PIDs is deliberate, see bug 95954. So I'll narrow this to existing, but invalid PIDs again.

trunk r1416

This bug was fixed in the package apport - 1.1-0ubuntu1

---------------
apport (1.1-0ubuntu1) karmic; urgency=low

  * New upstream release:
    - Drop some remaining distro specific pieces of code from non-backends.
    - Add hookutils methods for attaching relevant packages, greatly improve
      attach_alsa() for sound problem debugging.
    - Move launchpad crash database implementation from ever-breaking
      python-launchpad-bugs (screenscraping) to launchpadlib (official and
      stable Launchpad API). (LP: #353879)
    - Add new field Report.pid which gets set on add_proc_info() and can be
      used by hooks.
    - setup.py: Properly clean up all generated files, install missing
      mimetypes/text-x-apport.svg icon symlink.
    - Add README file.
    - Add translations from Launchpad.
    - Remove preloadlib/*; it's undermaintained, and not really useful any
      more these days.
    - Various bug fixes; most visible being the misnamed
      etc/default/apport.default file (which should just be
      etc/default/apport).
  * Merge some bug fixes from trunk:
    - launchpad.py: Send and read Date: field again, reverting r1128; it is
      useful after all. (LP: #349139)
    - report.py, add_proc_info(): Only add ProcAttrCurrent if it is not
      "unconfined".
    - ui.py: Detect invalid PIDs (such as for kernel processes) and give a
      friendly error message. (LP: #360608)
    - report.py, add_hooks_info(): Always run common hooks, and run source
      package hooks if we do not have a binary package name. (LP: #350131)
    - launchpad.py: Consider socket errors when connecting as transient, so
      that crash-digger doesn't stop completely on them.
  * Drop debian/apport.README.Debian, superseded by upstream README.
  * Drop debian/apport.links, done by upstream setup.py now.
  * debian/rules, debian/apport.preinst: Drop upgrade fix for misnamed default
    file again, was only necessary for intra-Jaunty upgrades.
  * debian/control: python-launchpad-bugs → python-launchpadlib dependencies.
  * debian/local/apport-collect: Drop launchpadlib login code, just use the
    CrashDatabase implementation from apport/crashdb_impl/launchpad.py.
  * Make package backportable to hardy and intrepid:
    - debian/control: Relax python-central buil-dependency to 0.5.6.
    - debian/rules: Determine DH_PYCENTRAL value ("include-links" vs.
      "nomove") based on the installed pycentral version.
    - debian/rules: Only supply --install-layout=deb when Python version is
      2.6.
  * apport/hookutils.py: Add docstring for attach_hardware, thanks Matt
    Zimmerman! (Merged from lp:~mdz/apport/hookutils)
  * apport/crashdb_impl/launchpad.py: Support older wadllib API
    where bug.date_created was a string instead of a datetime object.
    (Cherrypicked from trunk).
  * debian/control: Drop apport dependency to python-xdg, it's not required.
    (LP: #354172)
  * debian/control: Drop gdb from Depends: to Recommends:. (LP: #354172)
  * debian/local/apport-collect: Print a friendly error message instead of
    crashing if the bug number is not an integer. (LP: #351050)
  * debian/local/apport-collect: Change incomplete tasks back to "New" ...