This is what I get from trying to get APT archives from devuan:

E: Failed to fetch
tor+http://devuanfwojg73k6r.onion/merged/pool/DEBIAN-SECURITY/updates/main/p/php5/php5_5.6.39+dfsg-0+deb8u1_all.deb
SOCKS proxy socks5h://localhost:9050 could not connect to
devuanfwojg73k6r.onion (0.0.0.0:0) due to: Host unreachable (6)
E: Failed to fetch
tor+http://devuanfwojg73k6r.onion/merged/pool/DEBIAN-SECURITY/updates/main/p/php7.0/php7.0_7.0.33-0+deb9u1_all.deb
SOCKS proxy socks5h://localhost:9050 could not connect to
devuanfwojg73k6r.onion (0.0.0.0:0) due to: Host unreachable (6)
etc.

This is my sources.list (sources format):

Types: deb deb-src
URIs: tor+http://devuanfwojg73k6r.onion/merged
Suites: ascii ascii-updates ascii-security ascii-backports
Components: main contrib

I also have a Debian system, and configured it to use TOR (list format):

deb tor+http://vwakviie2ienjx6t.onion/debian stretch main contrib
deb-src tor+http://vwakviie2ienjx6t.onion/debian stretch main contrib

deb tor+http://sgvtcaew4bxjd7ln.onion/debian-security stretch/updates
main contrib
deb-src tor+http://sgvtcaew4bxjd7ln.onion/debian-security
stretch/updates main contrib

Right now it's able to reach the Debian .onion addresses:

Hit tor+http://sgvtcaew4bxjd7ln.onion stretch/updates/main Sources

Hit tor+http://sgvtcaew4bxjd7ln.onion stretch/updates/contrib Sources

Hit tor+http://sgvtcaew4bxjd7ln.onion stretch/updates/main armel
Packages
Hit tor+http://sgvtcaew4bxjd7ln.onion stretch/updates/contrib armel
Packages
Hit tor+http://sgvtcaew4bxjd7ln.onion stretch/updates/contrib
Translation-en
Hit tor+http://sgvtcaew4bxjd7ln.onion stretch/updates/main
Translation-en
etc.

Please let me know what other information might help.