> I find it annoying that it’s not public, though.

I second that.  Can't we create a similar file there [1] and use it
instead?  (BTW, could you add this link [1] to these pages [2,3]?)

[1] http://git.savannah.gnu.org/cgit/guix/maintenance.git/
[2] https://www.gnu.org/software/guix/
[3] https://savannah.gnu.org/projects/guix