automake warning skipping upgrade

[Scott Webster]

Hi folks.  This question is likely quite similar to many that have
come before, but my searches haven't helped me.  A couple of times
recently I've gotten the following message when upgrading some ports:

Warning: Skipping upgrade since automake 1.11.1_0 >= automake
1.11.1_0, even though installed variants "+universal" do not match "".
Use 'upgrade --enforce-variants' to switch to the requested variants.

Unfortunately I'm having some problems figuring it out since I'm not
actually upgrading automake.  most recently I was upgrading only three
ports, pkgconfig, ImageMagick and wine-devel and the warning came
after the pkgconfig step:

[/Users/swebster at skadi]$ sudo port -u upgrade outdated
--->  Computing dependencies for pkgconfig
--->  Fetching pkgconfig
--->  Attempting to fetch pkg-config-0.24.tar.gz from
http://distfiles.macports.org/pkgconfig
--->  Verifying checksum(s) for pkgconfig
--->  Extracting pkgconfig
--->  Configuring pkgconfig
--->  Building pkgconfig
--->  Staging pkgconfig into destroot
--->  Deactivating pkgconfig @0.23_1+universal
--->  Computing dependencies for pkgconfig
--->  Installing pkgconfig @0.24_0+universal
--->  Activating pkgconfig @0.24_0+universal
--->  Cleaning pkgconfig
--->  Uninstalling pkgconfig @0.23_1+universal
Warning: Skipping upgrade since automake 1.11.1_0 >= automake
1.11.1_0, even though installed variants "+universal" do not match "".
Use 'upgrade --enforce-variants' to switch to the requested variants.
--->  Computing dependencies for ImageMagick
<snip>

Any ideas on whether or not this is a problem or how to resolve it? I
have some ports as +universal since some require the 32-bit version
(wine I think)... but I thought I had everything figured out in that
realm (in terms of what ports require +universal).

[~@skadi]$ port installed | grep automake
  automake @1.11.1_0+universal (active)

Thanks,

Scott