You cannot find save-for-web in the menu because it is not there. The plugin name is webexport.
If you have Gimp 2.9.9 from the ppa then it will use the gimp-plugin-registry package from the gimp-edge repo. No webexport is included. Probably failed when compiling.
Why? The package gimp-plugin-registry has not basically changed since Gimp 2.6 plugins both compiled and python that do not work, ancient scripts made for another era. About time it was dumped. My advice move what you want to your Gimp profile then uninstall the package.
What to do about webexport. The attached comes from an older package, throws up error messages. The only function that works is exporting to jpeg and you can always get an estimate of file size from the regular Gimp jpeg export dialogue.
Unpack it, put in your Gimp 2.9 profile ~/.config/GIMP/2.9/plug-ins, check that it is still executable.
If you have Gimp 2.9.9 from the ppa then it will use the gimp-plugin-registry package from the gimp-edge repo. No webexport is included. Probably failed when compiling.
Why? The package gimp-plugin-registry has not basically changed since Gimp 2.6 plugins both compiled and python that do not work, ancient scripts made for another era. About time it was dumped. My advice move what you want to your Gimp profile then uninstall the package.
What to do about webexport. The attached comes from an older package, throws up error messages. The only function that works is exporting to jpeg and you can always get an estimate of file size from the regular Gimp jpeg export dialogue.
Unpack it, put in your Gimp 2.9 profile ~/.config/GIMP/2.9/plug-ins, check that it is still executable.