Reading from the socket tends to block.

[otrho]

Much of the response reading/parsing code uses a default timeout of 20 seconds (from session.d: Options.timeout) but I'm seeing the code just blocking if we try to read when there's no data.

Right now e.g., in append() when reading a continue response but getting a TRYCREATE it doesn't parse properly and blocks. I'll fix that specifically but there are probably many places in the reading/parsing which could block in a similar way (even with a timeout, which is strange.)