two ports (gputils and gnome-common) won't upgrade although being outdated

[mkae (Marko Käning)]

I have two ports shown as outdated:

$ sudo port selfupdate; port outdated
Password:
--->  Updating MacPorts base sources using rsync
MacPorts base version 2.2.0 installed,
MacPorts base version 2.2.0 downloaded.
--->  Updating the ports tree
--->  MacPorts base is already the latest version

The ports tree has been updated. To upgrade your installed ports, you should run
  port upgrade outdated
The following installed ports are outdated:
gnome-common                   2.34.0_1 < 3.6.0_0        
gputils                        0.13.7_0 < 1.2.0_0        

but when I try to upgrade them nothing happens:

$ sudo port upgrade outdated
--->  Scanning binaries for linking errors: 100.0%
--->  No broken files found.
$

What does this mean?

[mkae (Marko Käning)]

I realized that these two ports were installed, but inactive:

$ sudo port activate gnome-common @3.6.0_0 
--->  Deactivating gnome-common @2.34.0_1
--->  Cleaning gnome-common
--->  Activating gnome-common @3.6.0_0
--->  Cleaning gnome-common
$ sudo port activate gputils @1.2.0_0 
--->  Deactivating gputils @0.13.7_0
--->  Cleaning gputils
--->  Activating gputils @1.2.0_0
--->  Cleaning gputils
$

So, I guess this is rather a feature than a bug.