Empty theme directory when using build parameters

support
3

… Indeed.

All of that over an empty themes repository under themes/

$ ls -al themes/minimal
total 8
drwxr-xr-x 2 roman roman 4096 Jun 28 12:15 .
drwxr-xr-x 3 roman roman 4096 Jun 28 12:15 ..

@Hanzei is your themes dir populated with anything?