bug#12540: Usage of srcdir when valac is generating a header file

[Stefano Lattarini]

Thanks Nick for chiming in.  Your explanation is basically right:
Automake ought to place generated-but-distributed files in the
source directory rather than in the build directory, for two major
reasons:

  1. as you've noted, putting such files in builddir could cause
     inconsistencies in general, and sometimes weird bugs in the
     automatic dependency tracking; see also a report from Akim:
     <http://debbugs.gnu.org/cgi/bugreport.cgi?bug=10852>

  2. the distributed files should not be modified nor regenerated
     by a "make all" issued from the builddir of an extracted
     tarball (otherwise, what is the point of distributing them
     in the first place?); having such files in the srcdir allows
     "make distcheck" to catch and report such an inconsistency
     (because the distcheck runs with the srcdir set to readonly,
     so that any attempt to modify files in there will lead to a
     error).

Thus I'm closing this ticket as "Won't Fix".  Anyone who has doubts,
questions or objections is however free (actually encouraged!) to
continue the discussion here.

Regards,
  Stefano