Building kernel with fedpkg and custom config

Hello, 

I've tried to build a kernel with custom config following
https://fedoraproject.org/wiki/Building_a_custom_kernel

Building the kernel following that recipe works fine. 

$ fedpkg clone -a kernel
$ git checkout origin/f25
edit kernel.spec
# define buildid .local > %define buildid .local

$ fedpkg local

However I can't figure out the bit with the custom config. 

The instructions on the wiki say that: 
  "Enabling config options
   If there are configuration options that need to be adjusted for your build, you can add
changes in the config-local file. 
   This will override anything set in the rest of the defconfigs."


I've created the .config with "make xconfig"

But there is no config-local file anywhere, copying/renaming the .config to config-local
does nothing
There is a kernel-local file, copying the .config to kernel-local does nothing

I've also tried to replace the kernel-x64-86.config generated with build_configs.sh
with the .config I made with make xconfig, and then tried to run fedpkg local - but that
gives an error message (target for arch not found or something along those lines) 

So in short, how do I build a kernel with fedpkg with a custom config? It seems that the
wiki is lacking a crucial bit of information, or there's something wrong with the
fedpkg system for building kernels. 

regards