HHVM 4.144 is released! This release marks the end of support of 4.136; 4.137, 4.138, 4.139, 4.140, 4.143 remain supported, as do the 4.102 and 4.128 LTS releases. 4.141 and 4.142 were cancelled due to the holiday season.


  • The type checker now truncates the error message when printing out a type, in case of hanging the type checker if the type is complicated. The threshold can be configured via the hh_client --config type_printer_fuel=N option.
  • classname<E> where E is an enum now supports dynamic.

Breaking Changes

  • Local coeffects are enforced at runtime (previously coeffect errors were only reported in the type checker, not runtime).
  • An error will be thrown when a global is accessed in a read_globals context without an enclosing readonly modifier.