Something with my past two Ubuntu upgrades broke all the internal links on my blog running on Wordpress.
It turns out the upgrade process changed the name of the target link on the .htaccess symbolic link file under my Wordpress install directory.
After the install this is what was linked:
Notice the missing "." in .htaccess.
To fix it, I had to update the link to with
All the links work again!
.htaccess -> /etc/wordpress/htaccess
>> ln -sf /etc/wordpress/.htaccess .htaccess