I get this warning when using Collections package: Version 0.15.0-preview.21
“Class HashSetExtensions can not exist in multiple namespaces in the same file, even if one is excluded with preprocessor directives. Please move these to separate files if this is the case.”
I’m not sure what one is supposed to do to fix this: Any changes to files in the packages section are simply reverted almost as soon as Unity notices you’ve changed them. Granted it’s a preview package, but 8 months later this is still an issue?