Installability

• Support for OCaml 4.12 (#804, #826, Kate Deplaix).

• lwt_ppx now uses ppxlib. This introduce a transitive dependency to OCaml.4.04 (#807, Philippe Veber).

Bugfixes

• Catch exceptions in Lwt_react.of_stream (#809, Petter A. Urkedal).

• Avoid segfaults in Lwt_unix.tcsetattr (#798, Frédéric Fortier).

Additions

• fork method in Lwt_engine. This method is a noop in the released engines but it paves the way to a libuv-based engine (#811, Ulrik Strid, Anton Bachin).

• Lwt_main.abandon_yielded_and_paused for use in conjunction with Lwt.fork (#789, Julien Tesson).

• Lwt.wrap_in_cancelable to complete protect and no_cancel (#785).

• Support for IOV_MAX in Lwt_unix.IO_vectors.system_limit (#801, Pino Toscano).

• Lwt_unix.send_msgto (#805, Antonio Nuno Monteiro).

• Lwt.dont_wait, a more explicit alternative to Lwt.async (#820, François Thiré).

Miscellaneous

• Avoid double-reversing when traversing lists. This may change the order in which some promises are collected, which may change which of several rejection is arbitrarily selected during concurrent traversal (#784).

• Numerous documentation improvements (including external contributions from Bikal Lem, Sudha Parimala, and Hannes Mehnert).