Select/MultiSelect with data group undefined or empty string raise each child in a list should have a unique "key" prop.

[AntoineGst]

What package has an issue

@mantine/core

Describe the bug

When group is undefined or empty, a warning appear :

Warning: Each child in a list should have a unique "key" prop. 

What version of @mantine/hooks page do you have in package.json?

5.1

If possible, please include a link to a codesandbox with the reproduced problem

https://codesandbox.io/s/multiselect-with-empty-group-0gr59x

Do you know how to fix the issue

No response

Are you willing to participate in fixing this issue and create a pull request with the fix

No response

Possible fix

Introduce group label and group key separately instead of group to avoid this warning.

[rtivital]

Fixed in 5.1.5