mozilla/servo — pull request #2779 by Ms2ger (2014-07-07 14:55:09+00:00)
Title: Print a more helpful debug message when creating an element in the HTML parser.

Using {:?} prints a debugging representation such as

collections::string::String{
vec: collections::vec::Vec{
len: 4u,
cap: 4u,
ptr: (0x7f75670285d8 as *mut ())
}
}

which is not very helpful.