Tunnel HTTPS traffic through a proxy on Mac OS X

Tunnel HTTPS traffic through a proxy on Mac OS X

I am trying to route all my browser traffic through an HTTP proxy for
debugging reasons. I have tried mitmproxy and burp, with Firefox, Safari
and Chrome on Mac OS X.
The problem I'm having is that HTTP traffic is shown in the proxy and can
be logged, manipulated etc. but HTTPS traffic is only shown when I use
curl from the command line. When using one of the browser, HTTPS pages
load as normal, but they are not shown/logged in mitmproxy or burp. I
looks like the browser bypass the proxy for HTTPS requests.
What can I do to debug HTTPS connections?
EDIT (because I lack the reputation to answer myself): As a permanent
monument to my own stupidity, here is the answer:
In Mac OS X, two boxes need to ticked for the system (and thus the
browser) to use a HTTP proxy: one box for HTTP and another for HTTPS. I
had just ticked the HTTP box.