To be able to pass in a Sass command line option and have it include the true line-number of the css selector, into the style properties of the generated css file. This will allow you to easily jump to the line number for a selector vs having to try and do a [ctrl/cmd + f] in your code. This is different than [:debug_info] as it will actually include the line number in the css code that the browser shows us. For example:
sass --watch --style :expanded :line-numbers sass:css
.thisSelector {
background: #bada55;
font-size: 14px;
& .thisSelectorChild {
background: #f00;
float: left;
height: 40px;
}
}
.thisSelector {
-line-number: 145;
background: #bada55;
font-size: 14px;
}
.thisSelector .thisSelectorChild {
-line-number: 149;
background: #f00;
float: left;
height: 40px;
}