Upstream Proxy HTTPS

I have my script changing the upstream proxy for HTTP connections, but it seems to fail for HTTPS connections. Here’s a basic stripped down example.

The script works fine for, but fails for With HTTPS I see the following, which shows the upstream proxy wasn’t changed.

Server connection to default_proxy:8888 failed: Error connecting to "default_proxy": [Errno 8] nodename nor servname provided, or not known

Running Command:
mitmdump -s utilities/ -U http://default_proxy:8888

Platform / Library Version:

mitmdump --version
Mitmproxy version: 2.0.1 (release version)
Python version: 3.6.1
Platform: Darwin-14.5.0-x86_64-i386-64bit
SSL version: OpenSSL 1.1.0e 16 Feb 2017
Mac version: 10.10.5 (’’, ‘’, ‘’) x86_64

It looks like somebody maybe had a similar error here, and upgrading fixed it. But I’m already on 2.x.