Fixing the issue with apt caused by a bad local proxy: -1- Create 99fixbadproxy at: /etc/apt/apt.conf.d/99fixbadproxy -2- Run clear.sh

99fixbadproxy

Acquire::http::Pipeline-Depth "0";
Acquire::http::No-Cache=True;
Acquire::BrokenProxy=true;

clear.sh

#!/bin/bash
sudo rm  /var/lib/apt/lists/*
sudo rm  /var/lib/apt/lists/partial/*
sudo apt-get update

Can you explain the use and the terms in 99fixbadproxy

(Not an answer to the question above, just a backlink)
Relates SO question: https://askubuntu.com/questions/679233/failed-to-fetch-hash-sum-mismatch-tried-rm-apt-list-but-didnt-work

this helped me to work around a apt-get install issue about error "Hash Sum MIsmatch" in docker.

Also can set options at runtime:
apt-get -o Acquire::BrokenProxy="true" -o Acquire::http::No-Cache="true" -o Acquire::http::Pipeline-Depth="0"