Invalid backup directory

[akovia]

Hi,
I don't edit pkgbuilds much so I'm not sure when exactly this started, but now when I try I get this error.

( Unsupported package: Potentially dangerous ! )
==> Edit PKGBUILD ? [Y/n] ("A" to abort)
==> ------------------------------------
==> y

Invalid backup directory

Also getting this error when trying to manually select packages.

==> Continue upgrade ? [Y/n]
==> [V]iew package detail   [M]anually select packages
==> --------------------------------------------------
==> m
Invalid backup directory

I do see that it is using /tmp/yaourt-tmp-$USER/ successfully for building, so I'm not sure what is happening. I've never edited yaourtrc but I'm happy to post it if needed.