Running Vagrant in VirtualBox is a great way to make a local dev setup for any webdeveloper. Except for when you encounter the strangeness of the sendfile-bug in this combination which has been here for over 8 years now (!).
What happens is this; you create (say) a style.css and fill it with your complete css. Save it, refresh, ta-dah.
But then you decide to change something, and the changes don’t reflect. You refresh and you refresh, you clear all the caches, browse incognito mode, smash two keyboards to pieces by ramming CTRL+F5, and the changes still do not reflect.
So what do you do? Clean out the file – save it as empty and bam, there are your changes (well, the lack of actually).
So then you paste everything back; and you’re back at square one; no changes. Then you decide to leave out everything but just put one simple line in; now we see what’s happening. For some kind of mysterious reason the old css is always shown, but only the character amount of the (actual) file.
And the life of a developer goes on and on..
Edit: Apparently it’s some markup.