Cannot find messages after successfully creating them

edit

I am in the middle of creating a custom message. I have

1. created a package in my workspace
2. Create a folder called msg in the package folder
3. Create a message file there. The message does not depend on other custom messages
4. Modify package.xml to contain build depend and exec depend for message_generation and message_runtime

5. Modify CMakeLists.txt to 5.1 find_package with message_generation 5.2 add_message_files with my custom message file 5.3 generate_messages( with std_msgs) (I dont know if this is necessary 5.4 catkin_package( with CATKIN_DEPENDS message_runtime

6. from the workspace folder did catkin_make

I can see that the custom message is being generated (for lisp cpp eus nodejs and py)

However, after this I do

rosmsg show Mymessage

Could not find msg 'Mymessage'

and also if I list the messages with rosmsg list, it is not there

What is happening?

P.S

As predicted when I tried to use the message from a pythong program I got the

from myPackage.msg import Mymessage ModuleNotFoundError: No module named 'myPackage'

What?? The package is not being recognized as a module??