I tried to compile the latest uikit version but it fails hard with an error.

Problem is this type of selector:

:where([class*='foo']) p {
 // ...
}

To be more precise it's this at transition.scss:

:where(.uk-transition-fade),
:where([class*='uk-transition-scale']),
:where([class*='uk-transition-slide']) {
    --uk-position-translate-x: 0;
    --uk-position-translate-y: 0;
}

https://github.com/uikit/uikit/blob/87801983205aa9bb81a122c4e0f1b96b5117c169/src/scss/components/transition.scss#L51-L56

The error happens at array_diff which compares two incompatible nested array structures I guess:

Debug: