HHVM 4.74 is released! This release marks the end of support for 4.67; HHVM 4.68–4.73 remain supported, as do the 4.32 and 4.56 LTS releases.

Breaking Changes

• Previous versions of the typechecker checked for overridden final methods in two places; now this is consistently checked once in the typechecking phase, which can result in changed error codes.
• Single-quoted string shape keys that contain escape sequences (backslashes) are now handled the same way as other single-quoted strings. Previous versions would incorrectly include the backslash in the key.
• The typechecker now verifies method where constraints are well-formed; method generic constraints (e.g. public function foo<T as Bar>()) were already verified in this way.