Cannot load message class for [debug/mymessage] Are your messages built?

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I am having the very common problem stated in the title. There are already several questions and answers addressing this. Why am I posting this? Because no answer in those question address my particular problem. Let me explain

First, after I got the error I did:

1. Check that the devel/setup.bash is being sourced:
   In the code I work with, the folder devel is inside the folder build. So I cannot do source devel/setup.bash. Instead I do source build/devel/setup.bash Nevertheless the problem persists.

2. I searched for the mymessage.h. It exists included in the devel/include/debug/ folder

3. I have another message [interface/anothermessage] with topics that publish without problem. However none of these messages appear in rosmsg list.

4. I repeat, even though the topic of the message [interface/anothermessage] is publishing without problem, its message type does not appear in rosmsg list and if I do rosmsg show interface/anothermessage a lot of garbage appear after "unable to load the mssage.

5. My code does not use- at least directly catkin_make. I use cmake and make. I have built the code. when I do cmake I can see debug : 10 messages so the messages are generated

I have checked that in the debug folder that contain the message definition, its package.xml contains the build_depend and run_depend for message_generation and message_runtime (then again the messages seem to be generated.

What else can I check?