syntax error: expected name after class [pony/ponyc]

[killerswan]

Right after installing the latest pony-vim-syntax, and opening up some files in the latest ponyc master, I see this error.

Syntax has changed?

That's with syntastic set up more or less like so.

[Earnestly]

From here you can see that the error is generated from ponyc --pass=expr parentdir. Either the syntax has changed or ponyc --pass=expr is incorrect, try asking #ponylang on freenode.net or opening an issue at https://github.com/ponylang/ponyc/issues

From pony.g this should be valid as it indicates an optional cap after the class_def.