Please remember to use WikiFormatting when writing in Trac. Also, fill in the Port field and Cc that port's maintainer.
The log you attached says:
Skipping completed
This means this was not a clean attempt. So please run:
sudo port clean wxWidgets
and then try again and attach the new main.log if it fails again.
The incomplete log also says:
:info:configure checking for SDK directory /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.6.sdk... configure: error: not found
:info:configure See `config.log' for more details.
If the new log says the same thing, then please attach the config.log as well, and tell us whether that path actually exists, and tell us your Xcode version.
I expect that you have Xcode 4.4 or greater, which no longer includes the 10.6 SDK. See also #36156. If so, try the wxwidgets-devel port instead.