Why Tinyproxy Rejects an IPv6 Upstream Line
Diagnose IPv6 Tinyproxy Upstream parse errors against the exact release rather than assuming a network failure.
A parse failure on Tinyproxy's IPv6 Upstream line occurs before a network connection. Check the executable release before investigating DNS, IPv6 routes or passwords.
The 1.11.1 parser restricts upstream hosts to its IPv4/hostname forms. IPv6 support in other code paths does not make that directive accept an IPv6 literal.
The current project manual instead describes a protocol and bracketed IPv6 endpoint:
Upstream http [2001:db8::20]:8888The address is illustrative. Match documentation/source to the installed package, including distribution patches. Check proxy type, endpoint grammar and compiled upstream support as separate prerequisites.
A supported hostname form can avoid the literal grammar problem, but does not force IPv6 or fix address-family routing. A forum regex patch identifies a possible parser limitation; it does not validate every later connection stage. Resolve package compatibility first so a valid upstream is not blamed for a configuration the process never accepted.