Why did all my custom Gedit themes and language specs disappear after the 11.10 upgrade?

I recently upgraded to 11.10 on my desktop, but afterward all the custom themes I added and the MediaWiki syntax highlighting were gone.

For the themes, I forget where I put the files, but the syntax highlighting was downloaded according to the author's instructions so it is still at ~/.local/share/gtksourceview-2.0/language-specs/

What gives? I tried removing the files/directory and starting over, tried moving the directory to ~/usr/share... instead, tried restarting, tried updating my packages. No luck.

The new location for the language specs is ~/.local/share/gtksourceview-3.0/language-specs/ (note the 3 instead of the 2). If you put your .lang files there, they should work like they did before.

I'm not sure about the gedit themes. Are they actually gtksourceview styles? They have made the same move.

There is also an old folder ~/.gnome2/gedit on my system, and also one in ~/.local/share/gedit. You could try moving files from the first of these folders to the latter and see if that solves your issue.

Good question! I struggled to find the answer for a while, and finally found that language specs were relocated to:

/usr/share/gtksourceview-2.0/language-specs/
/usr/share/gtksourceview-3.0/language-specs/

Searching for all .lang files on my system, I found that there is also a gtksourceview-3.0 directory which shares many language files that are only slightly different (diff'ing each pair, most feature very small changes to licenses, etc).

After adding my .lang file to both folders, I was able to use the syntax highlighting I so dearly desired!