As per summary, check attached build log.
And _please_ try not to fix it in the wrong way: http://blog.flameeyes.eu/2009/07/02/how-_not_-to-fix-gcc-4-4-bugs
Created attachment 198055 [details]
Version 1.2.1 has been released in April, before this bug was filed, and it is still not in portage.
Debian have a patch for gcc 4.4 compatibility, and they have sent it upstream and it has been committed.
Two more bug fixes have been committed upstream besides the gcc 4.4 compatibility. Debian ship patches for both.
I attach the diff for a fixed version 1.2.1 ebuild and the three relevant patches.
I have removed the "-j1" from the call to emake because on my dual core machine -j3 appears to work fine. Please test and commit.
 - http://xplanet.svn.sourceforge.net/viewvc/xplanet?view=rev&revision=152
 - http://packages.debian.org/source/sid/xplanet
 - http://xplanet.svn.sourceforge.net/viewvc/xplanet?view=rev&revision=157
Created attachment 198080 [details, diff]
a bugfix from upstream, from Suse
Created attachment 198081 [details, diff]
a bugfix from upstream
Created attachment 198082 [details, diff]
gcc 4.4 compatibility patch, from upstream, from debian
Created attachment 198084 [details, diff]
the changes to the ebuild
Fixed, thanks :)