пт, 2 июн. 2023 г., 14:54 Andrea paz <gamberucci.andrea@gmail.com>:
@Stefan Thanks for the hint. I had done the copy/paste from
bld_appimage.sh which indeed reports the error (@Phyllis: better
correct this error?).
The compilation starts but stops with an error.

I did a new build with the 2 patches. This time the build happens
without any problems. The zscale plugin is present, but it keeps
getting the usual error when I change the color parameters.

PluginFVClient::process_buffer() F_zscale
  err: Generic error in an external library

:(

You tried to set parameters from down (input) to top?

Sorry, it just seems this plugin/underlaying library  behaves badly if you set only *some* parameters, because there is no way I know to set them all in one go (and anyway we can interactively change them individually and watch result realtime ....)