Issue Compiling Theme, removing some bootstrap stuff solves it

Hi all

I was having issues compiling in the theme area of template, not the complete compiler (that make sense??)
The general less compiler works fine

It was throwing up an error in the bootstrap/mixins.less file, line 47
I removed
// Sizing shortcuts
.size(@width; @height) {
width: @width;
height: @height;
}

It then threw an error in less/typography.less line 230:
I removed this line:
&:extend(.clearfix all); // Clear the floated `dt` if an empty `dd` is present

For now al seems to be good....

I have attached two images to demonstrate which compiler works fine and which one required me to delete some less code


Peace

Jon