Marius Bakke <mbakke@fastmail.com> writes:

> * gnu/packages/game-development.scm (sfml)[source](snippet): New field.
> [inputs]: Add STB-IMAGE and STB-IMAGE-WRITE.

[...]

> +              (modules '((guix build utils)
> +                         (ice-9 ftw)))

Whoops, (ice-9 ftw) is not needed (anymore ;-)).  Fixed locally.