Oh indeed it was !
export GUILE_LOAD_PATH=/usr/local/share/guile/site/3.0
Buuut wait for it
checking if (sdl2 image) is available… no configure: error: required guile module not found: (sdl2 image)
NOOOOES ! T_T I installed libsdl2-image-dev, doesn’t seem to help. Another variable tu set up ? :<