Stylus error example: Descendant selector by wykopchanger

/* ==UserStyle==
@name           Descendant selector AND general sibling selector with curly bracket in new line causes error
@version        1

@preprocessor   stylus
@namespace      userstyles.world/user/test2
@license        No License (YOU CAN USE THIS CODE ONLY IN STYLUS EXTENSIONS. You are not allowed to: copy any part of the code, share, and use it anywhere)
==/UserStyle== */   
@-moz-document url-prefix("https://google.com")
{
    // descendant selector with opening curly bracket in new line
    // THIS PRODUCES AN ERROR "Cannot read properties of undefined (reading 'block')"

/*
    div small
    {
        font-size: 0.7em;
    }
*/


    // general sibling selector with curly bracket in new line
    // THIS PRODUCES AN ERROR "Cannot read properties of undefined (reading 'block')"

/*    
    div ~ small
    {
        font-size: 0.7em;
    }
*/


    // child selector DOES NOT PRODUCE AN ERROR
    div > small
    {
        font-size: 0.7em;
    }
    // adjacent sibling selector DOES NOT PRODUCE AN ERROR
    div + small
    {
        font-size: 0.7em;
    }
    
    // element selector DOES NOT PRODUCE AN ERROR
    div
    {
        font-size: 0.7em;
    }
    
    // descendant selector with opening curly bracket in the same line
    // DOES NOT PRODUCE AN ERROR
    div small {
        font-size: 0.7em;
    }
    
    // general sibling selector with opening curly bracket in the same line
    // DOES NOT PRODUCE AN ERROR
    div ~ small {
        font-size: 0.7em;
    }
    




}