lang/gcc47 upgrade problems (was: lang/gcc46 dependency loop on lang/gcc)

[Gerald Pfeifer]

On Tue, 28 Aug 2012, Bryan Drewery wrote:
> I believe this was reported in ports/171135 as well for lang/gcc47.
> Received in private email:

This may or may not be the same issue.  In a case like this it
is always possible that one is missing the obvious, but right
now I am simply not seeing it.

Any chance to see where this dependency for lang/gcc47 on
itself is coming from?  Especially with the report that an
install followed directly by an upgrade triggers this?

On Wed, 29 Aug 2012, 唐 剑锋 wrote:
> I have tested in a new freebsd 9.0. 
> only install gcc47 then upgrade it.

Does this also happen if you do not have USE_GCC=4.7 in 
/etc/make.conf?

What exactly is the effect of that?  Does this not build
every other port with a dependency on gcc47?  If so, when
portupgrade temporarily remove gcc47, won't this impact
anything that portupgrade runs afterwards?

Is 

  pkg_delete: package 'gcc-4.7.2.20120818' is required by these other packages
  and may not be deinstalled (but I'll delete it anyway):
  .. (depends packages ignore)

the key perhaps?

Gerald