Can't find registered Python addon inside Blender 2.91.2 (tutorial example)

Question

I have exactly the same issue as here: Can't find my addon inside blender 2.90 (first addon). But in my case adding the addon Category didn't work.

Following this tutorial https://docs.blender.org/manual/en/latest/advanced/scripting/addon_tutorial.html, after installing Blender 2.91.2 I put the following script in Text editor and run it:

bl_info = {
    "name": "Move X Axis",
    "version": (1, 0),
    "blender": (2, 91, 2),
    "category": "Object",
}

import bpy


class ObjectMoveX(bpy.types.Operator):
    """My Object Moving Script"""      # Use this as a tooltip for menu items and buttons.
    bl_idname = "object.move_x"        # Unique identifier for buttons and menu items to reference.
    bl_label = "Move X by One"         # Display name in the interface.
    bl_options = {'REGISTER', 'UNDO'}  # Enable undo for the operator.

    def execute(self, context):        # execute() is called when running the operator.

        # The original script
        scene = context.scene
        for obj in scene.objects:
            obj.location.x += 1.0

        return {'FINISHED'}            # Lets Blender know the operator finished successfully.

def register():
    bpy.utils.register_class(ObjectMoveX)


def unregister():
    bpy.utils.unregister_class(ObjectMoveX)


# This allows you to run the script directly from Blender's Text editor
# to test the add-on without having to install it.
if __name__ == "__main__":
    register()

Then, I look for it in the menu search with no success:

I don't find it in Edit -> Preferences -> Add-ons neither.

I tried putting "blender": (2, 80, 0), like in the tutorial, removing "version": (1, 0), , with no result so far.

Answer 1

Actually in the tutorial you have mentioned above, it's 'Operator Search' not 'Menu Search' which you opened but may not noticed. So to have a correct result, you need to enable 'Developer Extras' first.

Then you will get 'Operator Search' in Edit Menu.

With 'Operator Search', you can find your first addon.

Answer 2

I uninstalled Blender 2.91.2 and installed Blender 2.80 instead, and it works there! The add-on is properly registered and callable after being run in the Text editor or direct installation.

I tried 2.90 and it didn't work there, so at some point between 2.80 and 2.90 something has been broken in the Python Add-on functionality. For the moment it's fine as 2.80 has everything I need.