What version are you running?
2.5
What's the URL of the page containing the problem?
any
What steps will reproduce the problem?

Increase size of Firefox screen (so window.devicePixelRatio > 1)
Modify your ReviewBoard's djblets.gravatars.get_gravatar_url_for_email() (perhaps because you don't want requests to go out to gravatar.com and you use local files instead), so the "gravatar url" does not contain any query-parameters, (e.g. it becomes "/avatars/email-address.png" instead of "https://www.gravatar.com/avatar/hash?s=32")
Look at any page on ReviewBoard


What is the expected output? What do you see instead?
Expected: page renders

Actual: page fails to render due to a ReferenceError in jquery.gravy.retina.js
Djblets.getGravatarForDisplay = function(url) {

    if (window.devicePixelRatio > 1) {

        var parts = url.split('?', 2),

            params,

            param,

            baseurl,

            size,

            i;
    if (parts.length === 2) {
        baseurl = parts[0];
        params = parts[1].split('&');

        for (i = 0; i < params.length; i++) {
            param = params[i].split('=', 2);

            if (param.length === 2 && param[0] === 's') {
                size = parseInt(param[1], 10);
                params[i] = 's=' +
                            Math.floor(size * window.devicePixelRatio);
            }
        }

        url = baseurl + '?' + params.join('&');
    } else {
        console.log('Failed to parse URL for gravatar ' + src);
    }
}

return url;

};
The console.log line fails, there is no such variable "src" -- was "url" meant?
What operating system are you using? What browser?
Linux, Firefox
Please provide any additional information below.