Kivy : Error weakly-referenced object (in a clock function) no longer exists

Question

So here is my error code I think there\'s something hard in this error, i looked on forums but couldn\'t find out.

And ... i have the error on my phone

Answer 1

The official documentation (Kv language Programming Guide) says to add 'strong' references such as id_name: id_name.__self__ in the KV code, but it is unclear where this is necessary. What's more, it did not solve the ReferenceError: weakly-referenced object no longer exists errors for me.

What did work is forcing Buildozer to use a specific version of hostpython3 by adding this to the requirements line of the buildozer.spec file:

python3==3.7.5, hostpython3==3.7.5

One more note: after adding the above to requirements, I went back and removed all my __self__ references and it still worked fine, so apparently these are no longer needed in Kivy KV language.

Credit for this goes to the beautiful answer from leo10011.

Update 2020-05-19: This bug reportedly has been fixed in Kivy 2.0.

Answer 2

What I usually do to keep a reference to e.g. my_object is to add my_object: my_object.__self__ line in the kv part of my root rule.

Since you haven't provide any code, I can't be more specific...