Error with make_buffer

[Iker Urdaniz]

I'm getting the following error when setting require("el.diagnostic").make_buffer in my statusline

E5108: Error executing lua [string "luaeval()"]:1: invalid value (function) at index 19 in table for 'concat'
stack traceback:
        [C]: in function 'run'
        [string "luaeval()"]:1: in main chunk