Python passes all arguments by reference. For mutable objects such as
a list used here, changing the object will change the original one. If
components_list is not set, this means the default value gets modified.
This lead to kernels getting checked with the wrong required components.
For example, when checking a kernel from community first with the
default component_list, it would get extended with all options needed
for a kernel in community. When checking another kernel from the
testing category, also with the default component_list, it would now
check for the community options in the testing kernel.
Related: https://stackoverflow.com/a/986145
Reviewed-by: Luca Weiss <luca@z3ntu.xyz>
Link: https://lists.sr.ht/~postmarketos/pmbootstrap-devel/%3C20230402124338.64886-1-ollieparanoid@postmarketos.org%3E
89cbae6d31