HHVM 4.143 is released! This release marks the end of support of 4.135; 4.136–4.140 remain supported, as do the 4.102 and 4.128 LTS releases. 4.141 and 4.142 were cancelled due to the holiday season.

Additional patch releases have been made for 4.102, 4.128, and 4.135-4.140, which change the typechecker to ignore any files in vendor/bin/; this is required for compatibility with Composer 2.2.


  • Compatible with Composer 2.2.
  • Added documentation on hover for readonly, extends, async, await, and concurrent keywords.
  • fb_intercept2() now supports functions that return readonly.

Breaking Changes

  • If an interface or class is <<__ConsistentConstruct>> but does not define a constructor, all subclass constructors must now be pure ([]). Alternatively, define a constructor on the interface or class to specify different capabilities. In previous versions, this can be enabled with the pure_default_consistent_constructors flag in .hhconfig.
  • DateTimeInterface::getTimestamp() is now pure; any custom implementations will need to also be pure.