mint-choose-debian-mirror does not support proxies

[Mauro]

Trying to run mint-choose-debian-mirror in a system behind a corporate proxy produces the following errors:
root@hoat:/# mint-choose-debian-mirror
Current server: 'http://mirror.rts-informatique.fr/linuxmint/debian' (latest)
An error occurred: Failed to connect to 2001:41d0:8:e386::1: Network is unreachable
An error occurred: Connection timed out after 10000 milliseconds
An error occurred: Connection timed out after 10000 milliseconds
An error occurred: Connection timed out after 10000 milliseconds
An error occurred: Connection timed out after 10000 milliseconds
An error occurred: Connection timed out after 10000 milliseconds
An error occurred: Connection timed out after 10000 milliseconds
An error occurred: Failed to connect to 2606:f400:400:0:65:175:128:102: Network is unreachable
An error occurred: Failed to connect to 2001:690:2200:9a01::50:143: Network is unreachable
An error occurred: Failed to connect to 2001:700:1300:feed::141: Network is unreachable
An error occurred: Connection timed out after 10001 milliseconds
An error occurred: Failed to connect to 2001:660:3004:4003::37:80: Network is unreachable
An error occurred: Failed to connect to 2a00:1f00:dc06:10::106: Network is unreachable
An error occurred: Failed to connect to 2001:df0:2ed:feed::feed: Network is unreachable
An error occurred: Connection timed out after 10001 milliseconds
Best server: None

The proxy is set in:
- /etc/apt/apt.conf
- the HTTP_PROXY and HTTPS_PROXY environment variables
- using the LMDE UI to set the proxy server

This was already discussed here:
http://forums.linuxmint.com/viewtopic.php?f=185&t=112047&start=60#p780987

Linux Mint version: LMDE with Update Pack 7

[Vlad Orlov (monsta)]

This tool is now discontinued. Use mintSources to select a mirror. If the problem appears there, file a separate bug report.