HHVM 4.61 is released! This release marks the end of support for 4.55; HHVM 4.56–4.60 remain supported, as does the 4.32 LTS release.


  • The typechecker no longer reports multiple redundant errors when a class (interface) is extended (implemented) with incompatible generic type parameters (example).
  • Fixed a bug where using array_unshift on a keyset could cause the keyset to contain multiple identical values.

Future Changes

  • Support for HH_IGNORE_ERROR may be removed in the future, making HH_FIXME the only way to silence typechecker errors.
    • You can add disable_hh_ignore_error=true to your .hhconfig to get this behavior now.