Less on Node: @import path isn't relative to stylesheet

app.js

var express = require('express');
var app = express.createServer();

app.configure(function () {
    app.use(express.compiler({
        src: __dirname,
        enable: ['less']
    }));
    app.use(express.static(__dirname));
    app.use(express.errorHandler({
        dumpExceptions: true,
        showStack: true
    }));
});

app.listen(8888);
console.log('Listening at http://localhost:8888/ ...');

styles-slash-a.less

@COLOR: 'red';

.container (@marginVert: 1em) {
    margin: @marginVert auto;
}

html {
    color: @COLOR;
    .container();
}

styles-slash-b.less

@import 'a';

body {
    color: @COLOR;
    .container(2em);
}

(Gist doesn't show directories in filenames; place a.less and b.less inside a styles directory next to app.js.)

Run this Express app (node app.js), open your browser, and view http://localhost:8888/styles/a.css -- it should properly return:

html {
    color: 'red';
    margin: 1em auto;
}

But if you try to visit http://localhost:8888/styles/b.css in your browser, it won't work. Your node terminal will show:

file 'a.less' wasn't found.

Seems incorrect, no? When I debugged, it seems that Less operates off of the current working directory -- which is the directory above styles if you ran node app.js.

@import paths should work relative to the stylesheet, no? That's how regular CSS works in the browser, and I'm guessing LESS in the browser too.