Error: Orphaned: @unexec rmdir "/home" >/dev/null 2>&1 || :

[Gerald Pfeifer]

Build with a non-standard PREFIX and LOCALBASE in /home/gerald/10-i386,
make ports builds have been failing with the following for a bit (for
lang/gcc49 among others):

  #### Running regression-test, checking for orphans, checking pkg-plist.
  ====> Checking for pkg-plist issues (check-plist)
  ===> Parsing plist
  ===> Checking for items in STAGEDIR missing from pkg-plist
  Error: Orphaned: @unexec rmdir "/home/gerald" >/dev/null 2>&1 || :
  Error: Orphaned: @unexec rmdir "/home" >/dev/null 2>&1 || :

Any ideas what is going on here?  And what is adding those interesting
@unexec rmdir entries?  

Either these should not be added, or check-plist should not error out
when seeing them.

Gerald