You can clone with
HTTPS or Subversion.
When including a css file that happens to be empty, the following error will occur:
SCRIPT5007: Unable to get property 'replace' of undefined or null reference
selectivizr.js, line 428 character 4
I suspect this happens because on line 391, xhr.responseText will be undefined, instead of an empty string.
Tested on IE10-as-IE8 on Windows 7.