Cause
This error indicates that MacPorts successfully fetched the py25-py2app-devel source but was unable to install it (unable to execute its “destroot” stage, technically) because it was unable to find and move a file called NEWS.txt. A quick look at the py2app source tree reveals that NEWS.txt is indeed gone, although the port still tries to install it—see line 38 in the latest Portfile. (Portfiles are the instructions for building and installing MacPorts software.)
Short-term fix
Make sure you have the latest version of the MacPorts core software and ports tree. This is almost always a good idea. Do this by opening Terminal and running the following command:
sudo port selfupdate
Clean out all temporary work/build files left over from your unsuccessful install by running
sudo port clean --all py25-py2app-devel
This ensures that MacPorts starts from a clean slate the next time you try to install the port.
Remove the reference to NEWS.txt in the py25-py2app-devel Portfile so that it doesn’t try to install NEWS.txt anymore; the file is located at $(port dir py25-py2app-devel)/Portfile. A quick way to do this is by running
sudo sed -i '' '38s/NEWS.txt//' $(port dir py25-py2app-devel)/Portfile
This command removes the text “NEWS.txt” from line 38 of the Portfile for py25-py2app-devel. This is the only reference to NEWS.txt in the Portfile.
Try installing again:
sudo port install py25-py2app-devel
The port should install correctly this time, unless some other unforeseen problem crops up. At the very least, you shouldn’t have the NEWS.txt problem again.
Long-term fix
While this should work for you, updating your tree again with port selfupdate will overwrite your local changes with the incorrect Portfile from MacPorts. (This won't break your installation, but it means reinstalling later will fail, unless someone else patches it on MacPorts’s end.) If the fix above does work, let me know and I can submit a patch. Or you can do it yourself, if you’re feeling adventurous. :)
