John Flinchbaugh Blog: Porting Scripts for GIMP 3.0

GIMP 3.0 hit my Linux machines a while ago, and all my personal and 3rd-party scripts broke.

I finally took a moment to look at the errors and figure out what needed to be updated.

My simplest script merely sets the current layer’s blend mode to Soft Light, but even that broke. Why’s that useful? Once there’s an action in the menu, I can bind a keyboard shortcut (Ctrl-S) to it. I need to switch lots of new layers to Soft Light: High Pass for sharpening, or a layer for dodging and burning.

Registering the menu is what often failed:

attempted to install procedure ""
with a full menu path "<Image>/Shortcuts/_Change to Softlight" as menu label,
this is not supported any longer.

To fix it, we move the menu path into a separate call, instead of all at once in script-fu-register.

Here’s the fixed script:

(define (softlight-layer img inLayer)
  (gimp-layer-set-mode inLayer LAYER-MODE-SOFTLIGHT)
    (gimp-displays-flush))

(script-fu-register
    "softlight-layer"                         ;function name
    "Change to Softlight"                     ;menu label
    "Change current layer to Softlight mode"  ;description
    "John Flinchbaugh"                        ;author
    "Copyright 2025, John Flinchbaugh"        ;copyright notice
    "November 26, 2025"                       ;date created
    "RGB* GRAY*"                              ;image type that the script works on
    SF-IMAGE "image" 0
    SF-DRAWABLE "drawable" 0)

(script-fu-menu-register "softlight-layer" "<Image>/Shortcuts")