[Pkg-privacy-maintainers] Bug#968159: torbrowser-launcher: "Error starting download" using local or remote tor socks5 proxy server

[tubby-tor]

Package: torbrowser-launcher
Version: 0.3.2-11

Using the torbrowser-launcher to download the Tor Browser over tor fails both for a local tor socks5 proxy and also a remote tor socks5 proxy.  In both cases, the socks5 proxies were tested to be working by downloading the Tor Browser using "curl --socks5-hostname".

Tor Browser Launcher Settings:
Download over system Tor: Checked
Tor server: 127.0.0.1:9050 (local tor)
Tor server: 192.168.1.1:9050 (remote tor)

In the case of the remote tor socks5 proxy, the server is running on 192.168.1.1 and the client is 192.168.1.2 (for the purposes of the test case).

The error is:
"Error starting download:"
"Trying to download over Tor. Are you sure Tor is configured correctly and running?"

Downloading using curl --socks5-hostname works:
# cd /tmp
# curl --remote-name --socks5-hostname 127.0.0.1:9050 https://dist.torproject.org/torbrowser/9.5.3/tor-browser-linux64-9.5.3_en-US.tar.xz
# curl --remote-name --socks5-hostname 127.0.0.1:9050 http://rqef5a5mebgq46y5.onion/torbrowser/9.5.3/tor-browser-linux64-9.5.3_en-US.tar.xz
# curl --remote-name --socks5-hostname 192.168.1.1:9050 https://dist.torproject.org/torbrowser/9.5.3/tor-browser-linux64-9.5.3_en-US.tar.xz
# curl --remote-name --socks5-hostname 192.168.1.1:9050 http://rqef5a5mebgq46y5.onion/torbrowser/9.5.3/tor-browser-linux64-9.5.3_en-US.tar.xz

Additionally, on the system with a standard Debian tor installation (thus a local sock5 proxy), the torify or torsocks also works on the torbrowser-launcher.
# torify torbrowser-launcher

torbrowser-launcher should work correctly either with a local or remote tor socks5 proxy.

# tor --version
Tor version 0.4.3.6.

# apt search torbrowser-launcher
torbrowser-launcher/testing,now 0.3.2-11 amd64 [installed]