/usr/share/fonts-font-awesome/less/fixed-width.less is in fonts-font-awesome 4.0.0~dfsg-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 | // Fixed Width Icons
// -------------------------
.@{fa-css-prefix}-fw {
width: (18em / 14);
text-align: center;
}
|