CHANGES

===== dev =====

====== Additions ======

  * Lwt_seq: a Seq-like data-structure with Lwt delayed nodes (#836, Zach Shipko).

====== Bugfixes ======

  * Fix Lwt_fmt.stderr to actually point to stderr (#852, #850, Volker Diels-Grabsch).

===== 5.4.0 (2020-12-16) =====

====== 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).



===== 5.3.0 (2020-04-22) =====

  * Add let* and and* in Lwt.Syntax and Lwt_result.Syntax (#775, Rahul Kumar).
  * Also add let+ and and+ (#776, Craig Ferguson).
  * Add Lwt_result.both (#775, Rahul Kumar).
  * Always use libev if detected (#601).

===== 5.2.0 (2020-03-09) =====

  * Add Lwt_unix.pread, Lwt_unix.pwrite, and Lwt_unix.pwrite_string (#768,
    Pierre Chambart).
  * Internally use accept4(2) when available (#769, Pierre Chambart).
  * PPX: internally use 4.10 ASTs (#765).

===== 5.1.2 (2020-02-23) =====

====== Bugs fixed ======

  * Do not run C exit hooks after failed exec (#764, diagnosed Lucian Wischik).
  * discover.ml: don't add flags for missing system libraries (#760, #761, Olaf
    Hering).
  * discover.ml: don't run the opam binary (#761).
  * Warning on 4.10 in lwt_unix_stubs.c (#766).

===== 5.1.1 (2020-01-07) =====

====== Bugs fixed ======

  * Exception raised by Lwt_main.run upon call to exit (#758, reported Gal
    Schlezinger).

===== 5.1.0 (2019-12-28) =====

====== Additions ======

  * Lwt.all (9976f67).

====== Documentation ======

  * Add index.mld for nicer odoc output (1059a80, prompted Anurag Soni).
  * Link to rwo-lwt from the online manual to make it more discoverable
    (4129a22, suggested Anurag Soni).
  * Fix doc links in opam files (7617607).

===== 5.0.1 (2019-12-22) =====

====== Bugs fixed ======

  * Additional fix for libev detection under esy (#757, Antonio Nuno Monteiro).

===== 5.0.0 (2019-12-15) =====

====== Breaking ======

See #584 for an extended summary and discussion of this release as a whole, or
individual issues for each change specifically.

  * The callback passed to Lwt.async must now evaluate to unit Lwt.t, rather
    than _ Lwt.t (#603, requested @cfcs).
  * Lwt.choose, Lwt.nchoose, Lwt.nchoose_split, Lwt.pick, and Lwt.npick now
    raise Invalid_argument if given the empty list (#557, Tim Reinke).
  * Catch nested calls to Lwt_main.run (#607, #609, prompted François-René
    Rideau).
  * Use the new Lwt_unix.IO_vectors in Lwt_unix.recv_msg and Lwt_unix.send_msg
    (#594, prompted Marcello Seri).
  * Make Lwt_unix.Async_switch a synonym for Lwt_unix.Async_detach (#572).
  * Remove the redundant configure.ml (#700).
  * PPX: remove support for general [%lwt ...] expressions (#527).
  * PPX: remove support for Lwt_log and the -log option (#520).
  * PPX: remove the -no-debug option (#528).

====== Bugs fixed ======

  * libev detection under esy (#755, Antonio Nuno Monteiro).

===== 4.5.0 (2019-12-15) =====

====== Additions ======

  * Implement Lwt_unix.readv and Lwt_unix.writev on Windows using Lwt_unix.read
    and Lwt_unix.write (#745, requested Ulrik Strid).
  * Implement Lwt_unix.wait4 on Android using Unix.waitpid, as on Windows (#752,
    @EduardoRFS).
  * LWT_DISCOVER_ARGUMENTS=--verbose flag, passed through environment variable,
    for debugging the feature discovery (configuration) process (#740).

====== Bugs fixed ======

  * To help with fork, don't call back into Lwt_main at process exit to call Lwt
    exit hooks when there are none (#737, prompted Martin Jambon).
  * Properly retain references to buffers in Lwt_unix.readv, Lwt_unix.writev,
    Lwt_bytes.read, Lwt_bytes.write, and Lwt_bytes.mincore; the references could
    be released too early in rare circumstances (#742, prompted Olaf Hering).
  * Don't install a SIGCHLD handler when Lwt is linked in but not used (#738,
    requested Sam Goldman, additional information Waleed Khan).
  * Link with -lpthread on more platforms that support and require the flag
    (#748, Olivier Andrieu).
  * Fix syntax errors in feature test programs (#748, Olivier Andrieu).
  * C warning with OCaml 4.10 (#751, @kit-ty-kate).

====== Miscellaneous ======

  * Make tests more reliable (#726, #743, prompted Olaf Hering).
  * Fix deprecation annotation on internal API (#735, Antonio Nuno Monteiro).
  * Fix broken link in Lwt_mvar docs (#739, reported @tg-x).
  * Fix broken links in README (#750, @imbsky).

===== 4.4.0 (2019-10-09) =====

====== Additions ======

  * ?suffix argument for Lwt_io.with_temp_file and Lwt_io.open_temp_file (#724,
    requested Volker Diels-Grabsch).
  * Lwt_io.with_temp_dir and Lwt_io.create_temp_dir (#724, requested Volker
    Diels-Grabsch).

====== Changes ======

  * Lwt_io.establish_server: increase default backlog from 5 to SOMAXCONN (#731,
    suggested Konstantin Olkhovskiy).
  * PPX: use OCaml 4.09 ASTs to support recent features (074f679).
  * PPX: deprecate let%lwt structure items (#733, prompted Didier Le Botlan).

====== Miscellaneous ======

  * Tests now pass in more environments (#721, #722, #725, #729, reported Olaf
    Hering).

===== 4.3.1 (2019-09-26) =====

====== Bugs fixed ======

  * Lwt clobbered backtraces (#714, 6e855b8, 4694853, reported Volker
    Diels-Grabsch).
  * Lwt_unix.fork was broken on glibc 2.28 (#704, @ygrek).
  * Fix build with musl-gcc (#718, #719, reported Fabian Hemmer).
  * Support more Lwt_unix.madvise options (#716, Anton Kochkov).

====== Miscellaneous ======

  * Silence configure script (#717, requested Anil Madhavapeddy).
  * Greatly sped up CI and tests.

===== 4.3.0 (2019-08-20) =====

====== Planned to break in 5.0.0 ======

  For general discussion of breakage in Lwt 5.0.0, see #584. See #293 about how
  Lwt announces and does breaking changes.*

  * The signature of Lwt.async will change from (unit -> 'a Lwt.t) -> unit to
    (unit -> unit Lwt.t) -> unit (#603, prompted @cfcs).
  * Lwt_unix.send_msg and Lwt_unix.recv_msg will be changed to take
    Lwt_unix.IO_vectors.t instead of Lwt_unix.io_vectors (#702, prompted
    Marcello Seri).
  * Nesting calls to Lwt_main.run will be forbidden, and will raise an
    Failure. Most programs don't do this (#609, prompted François-René Rideau).
  * configure.ml will be removed in favor of an improved discover.ml This
    affects only users who are configuring Lwt as part of a manual installation
    (i.e., not users of opam or esy). See discover.ml for usage (#700).
  * Lwt_unix.async_method will have no effect. In practice, it already does
    nothing, and has almost no users (#572).

====== Additions ======

  * Lwt_process: allow setting working directory for new processes (#694, Thomas
    Leonard).
  * PPX: use OCaml 4.08 ASTs to support latest features (#697).
  * Lwt_io.NumberIO: use compiler intrinsics for better performance (#178,
    requested Mauricio Fernandez).

====== Bugs fixed ======

  * Race condition in Lwt_react.S.limit (4e592eb).
  * Use fallback rule during configuration (#693, Hongchang Wu).
  * Fix typos (#688, #692, @Fourchaux).

===== 4.2.1 (2019-04-02) =====

====== Bug fixed ======

  * Detect libev correctly when building under esy (#679, Antonio Nuno
    Monteiro).

===== 4.2.0 (2019-03-25) =====

====== Additions ======

  * Lwt.both (#668, Brendan Long, Jeremy Yallop).
  * ppx_let support with open Lwt.Infix (#667, Brendan Long).
  * Lwt_stream.of_seq (#646, Hezekiah Carty).
  * Lwt_io.is_closed (#635, Andreas Garnaes).
  * Lwt_unix.IO_vectors.byte_count (#645, Raphaël Proust).
  * Support for higher baud rates in Lwt_unix.tcgetattr and Lwt_unix.tcsetattr
    (#678, Frédéric Fortier).
  * Replacement functions in Lwt_main for deprecated functions based on
    Lwt_sequence (#660).

====== Bugs fixed ======

  * 4.08 compatibility (#658).
  * Stack overflow in Lwt_stream.iter_p (#432, Varun Kohli).
  * Incorrect bounds check in Lwt_bytes.mincore (#627, Cédric Le Moigne).
  * Lwt_bytes.mincore will not be available in future releases of OpenBSD (#663,
    Kenneth Westerback).
  * Missing header in the Android build (#652, Justus Matthiesen).
  * Build broken on MSVC (98303de, 85535f7, Dmitry Bely).
  * Build broken on OpenBSD (#672, Christopher Zimmermann).
  * Lwt_io.of_bytes produces a channel with inaccurate positions (#636, Nathan
    Rebours).
  * Lwt_io._.read_int behaves incorrectly on 32-bit systems (#671, reported
    Dmitry Bely).
  * Inaccurate locations for errors related to ;%lwt (#602, @kandu).
  * (_ : t) not recognized as a catch-all pattern by the PPX (#640, Florian
    Angeletti).
  * Race condition in Lwt_react.E.limit (#606, Avni Fatehpuria).
  * Premature deallocation in Lwt_react.E.with_finaliser and
    Lwt_react.S.with_finaliser (#626, El-Hassan Wanas).

====== Miscellaneous ======

  * New tests for Lwt_bytes, portions of Lwt_unix (#619, #621, #628, #630, #673,
    Cédric Le Moigne, Anurag Soni).
  * Test suite improvements (#656, Dave Parfitt).
  * Clarifications for documentation of Lwt.try_bind, Lwt.pick (#648, #650,
    Bikal Lem).
  * Fixed documentation of Lwt_io.read_line (#657, Yoni Levy).
  * Fixed some typos (#611, #613, Rich Neswold).

===== 4.1.0 (2018-06-26) =====

====== Additions ======

  * Change license to MIT (#560).
  * Lwt_fmt, an Lwt-aware version of Format (#548, Gabriel Radanne).
  * Lwt_io.establish_server_with_client_socket (#586).

====== Bugs fixed ======

  * Lwt_stream.iter_n: rename ?max_threads argument to ?max_concurrency (#581,
    Hezekiah Carty).
  * PPX: reject match expressions that have only exception cases (#597, Raphaël
    Proust).

====== Miscellaneous ======

  * Improvements to Lwt_pool docs (#575, Bobby Priambodo).
  * Restore all PPX tests (#590, Jess Smith).

===== 4.0.1 (2018-04-13) =====

====== Bugs fixed ======

  * Race condition in worker thread management in Lwt_unix (#569, diagnosed Gabe
    Levi).
  * Hang in Lwt_unix.read on Windows (#574, #569, 86a6baf, diagnosed Gabe Levi).
  * Docs: note that Lwt_io.open_file for writing truncates the file by default
    (#570, reported Tóth Róbert).

===== 4.0.0 (2018-03-30) =====

====== Breaking ======

These changes were announced in Lwt 3.1.0 and Lwt 3.2.0. See #453 about smooth
upgrade paths.

  * Delete package lwt.ppx. The PPX syntax is in package lwt_ppx since Lwt 3.2.0
    (#338).
  * Remove >> syntax from the PPX (#495).
  * Delete modules Lwt_log, Lwt_daemon, Lwt_log_core, and package lwt.log. These
    are in package lwt_log since Lwt 3.2.0, but it is recommended to use
    Logs_lwt from the logs library instead (#484, initiated Hannes Mehnert).
  * Delete package lwt.preemptive. It is an alias for lwt.unix since Lwt 3.2.0
    (#487).
  * Delete package lwt.syntax. The Camlp4 syntax is in package lwt_camlp4 since
    Lwt 3.2.0 (#370).
  * Delete module Lwt_chan, a predecessor of Lwt_io (#441).
  * Delete package lwt.simple-top, a predecessor of utop (#371).
  * Make resolvers (Lwt.u) contravariant (#458).

====== Planned to break in 5.0.0 ======

  * Lwt.pick will raise Invalid_argument on the empty list, instead of returning
    a forever-pending promise. Also applies to Lwt.choose, Lwt.npick,
    Lwt.nchoose, and Lwt.nchoose_split (#562, Tim Reinke, prompted Hezekiah
    Carty).
  * Remove translation of [%lwt ...] to Lwt.catch from the PPX (#527).
  * Remove -no-debug option from the PPX (#528).
  * Remove Lwt_log support from the PPX (#520).

====== Bugs fixed ======

  * Lwt_io.file_length now fails with EISDIR when used on a directory (#563,
    requested Cedric Cellier).
  * Lwt_react.E.limit and Lwt_react.S.limit now working more correctly (#566,
    @Freyr666).

====== Miscellaneous ======

  * Documentation improvements (#561, Jason Evans).

===== 3.3.0 (2018-03-07) =====

====== Bugs fixed ======

  * Restore backtrace support (#554, #556, Gabe Levi).
  * Serious logic error that could cause Lwt to hang or crash (#549, reported
    @koen-struyve).
  * All Lwt_list functions are now tail-recursive (#538, Joseph Thomas).

====== Additions ======

  * Support ;%lwt syntax in the PPX (#307, Hezekiah Carty).
  * Lwt_stream.iter_n (#312, Hezekiah Carty).

====== Miscellaneous ======

  * Testing improvements (#536, #541, @cedlemo).
  * Documentation improvements (#544, #546, #547, #553, #559, Daniil Baturin,
    Jason Evans, Jess Smith, Milo Turner).

===== 3.2.1 (2018-01-11) =====

Lwt 3.2.1 is released because it still packages lwt.ppx, a deprecated copy of
package lwt_ppx, and the two packages should be kept in sync.

====== Deprecations ======

  * All PPX options are deprecated and should not be used (#534).
  * The [%lwt ...] PPX syntax should be replaced by Lwt.catch (#534).

====== Fixes ======

  * Clean up PPX -help usage message output (#525, Zan Doye).

====== Miscellaneous ======

  * More thorough testing (#512, #535, Joseph Thomas).
  * Clarification of the C binding (#521, @cedlemo).

===== 3.2.0 (2017-12-19) =====

====== Additions ======

  * Lwt_mvar.take_available, Lwt_mvar.is_empty (#459, Hezekiah Carty).
  * Lwt_io.open_temp_file, Lwt_io.with_temp_file (#467, Joe Thomas).
  * New reference documentation for module Lwt (#469).
  * Lwt_pool.clear and ?dispose argument for Lwt_pool.create (#483,
    Hezekiah Carty).
  * Lwt_pool.wait_queue_length (#493, Jerome Vouillon).

====== Bugs fixed ======

  * Lwt.npick never worked (#447, Zack Coker).
  * Lwt_pool.use now always calls ?validate on elements (#461, Joe Thomas).
  * Better locations generated by the PPX (#470, Fabian Hemmer).
  * Keep worker thread count accurate in Lwt_unix when pthread_create fails
    (#493, @koen-struyve).
  * Leaked exceptions in Lwt_list (#499).
  * Memory leak in Lwt_unix.getnameinfo (#503, Hannes Mehnert).

====== Planned to break in 4.0.0 ======

See #453 for details and instructions about planned breakage in Lwt 4.0.0.

  * The semantics of Lwt will be adjusted for better exception and stack safety
    (#500).
  * The PPX will be factored out into its own opam package, lwt_ppx. This
    package is installable from opam now, as of Lwt 3.2.0 (#338).
  * Similarly, the deprecated Camlp4 syntax will be factored out into
    lwt_camlp4, which is installable from opam now (#370).
  * Modules Lwt_log, Lwt_log_core, Lwt_log_rules, and Lwt_daemon are being
    deprecated and factored out into opam package lwt_log, also installable from
    opam now. Use the logs library for logging, in particular module Logs_lwt.
    Direct daemonization is deprecated on most platforms (#484, Hannes Mehnert).
  * The >> construct from the PPX will be deleted (#471, Raphaël Proust).
  * Package lwt.preemptive is being merged into lwt.unix. In 3.2.0,
    lwt.preemptive becomes an alias for lwt.unix, and the package name
    lwt.preemptive will be deleted in 4.0.0 (#487).

====== Deprecations ======

  * Lwt.waiter_of_wakener should not be used, as it can lead to soundness bugs
    in future (but not current) Lwt (#458).
  * Lwt_sequence was deprecated in Lwt 2.6.0, but it now has a warning attached,
    as do Lwt.add_task_r and Lwt.add_task_l, which use it (#361).
  * Use of the following functions is discouraged, but they have not yet
    received deprecation warnings: Lwt.with_value, Lwt.cancel, Lwt.state,
    Lwt.ignore_result (#359, #469).

====== Miscellaneous ======

  * Replace references to Camlp4 in the manual with the PPX (#457, Bobby
    Priambodo).
  * More tests for Lwt_pool (#464, Joe Thomas).
  * Expect tests for the PPX (#474, Fabian Hemmer).

===== 3.1.0 (2017-07-19) =====

====== Additions ======

  * Port to Jbuilder (#374, Andrew Ray).
  * Lwt_io.establish_server_with_client_address (#346, Rudi Grinberg).
  * Lwt_unix.getcwd (#403, Raphaël Proust).

====== Planned to break in 4.0.0 ======

  * Delete lwt.simple-top (#371).
  * Delete Lwt_chan (#441).

====== Fixes ======

  * Make Lwt_log functions tail-recursive (#348, Jan Doms).
  * Make more of Lwt_list tail-recursive (#347, Jan Doms).
  * Improve string messages in exceptions (#368, #382, Jan Doms, Raphaël
    Proust).
  * Don't call Unix.set_nonblock or Unix.clear_nonblock unnecessarily on
    some fds (#356, David Sheets).
  * Lwt_unix.sleep and Lwt_unix.timeout returning too early when using
    libev (#433, Stijn Devriendt).
  * Lwt_sequence.fold_r iterating the wrong way in some cases (#405,
    Stijn Devriendt).
  * Build conflicts in some cases due to duplicate cst_to_constr
    function (#362, Jérémie Dimino).
  * Don't use deprecated readdir_r system call (#430, Raphaël Proust).

====== Miscellaneous ======

  * The Lwt core, lwt.ml, has been thoroughly refactored and commented
    (#354, reviewed Gabriel Radanne, Edwin Török, Raphaël Proust, Jan
    Doms, Fabian Hemmer, Sebastien Mondet, Simon Cruanes, Anil
    Madhavapeddy, Pierre Chambart, and many others).
  * Lots of tests for most of the Lwt core (#339, #389, #392, #440,
    #448, #450, Joseph Thomas, Ryan Slade).
  * Documentation fixes (including by Joseph Thomas, Raphaël Proust,
    Richard Degenne, Stavros Polymenis).
  * Contributing documentation (#379).
  * Massively adjust whitespace for legibility (#400, #409, #416,
    Richard Degenne).
  * Improvements to CI (Etienne Millon, Raphael Rafatpanah, Zack Coker,
    Yotam Barnoy).
  * The additional packages lwt_ssl, lwt_react, lwt_glib get new minor
    releases, the change being new Jbuilder build systems (#374, Andrew
    Ray).

===== 3.0.0 (2017-04-10) =====

====== Breaking ======

  * These changes were originally announced in release 2.7.0 (#308).
  * Lwt_engine.libev now has an optional argument for selecting the libev back
    end (#269, #294, Jeremy Yallop).
  * Lwt_io.establish_server has been changed to make it more difficult to leak
    file descriptors (#258, #260).
  * Lwt_io.shutdown_server now evaluates to a promise, which completes when the
    listening socket's close(2) operation completes (#259).
  * Lwt_unix.bind now evaluates to a promise, because the bind(2) system call
    can block for Unix domain sockets (#296, requested David Sheets).
  * ocamlfind packages lwt.react, lwt.ssl, lwt.glib are replaced by lwt_react,
    lwt_ssl, lwt_glib. These have been separate OPAM packages, under those
    names, since 2.7.0 (#301).

===== 2.7.1 (2017-04-08) =====

====== Fixes ======

  * OCaml 4.05 compatibility (Mauricio Fernandez, #322).
  * Give Lwt_unix.file_exists the same semantics as Sys.file_exists, with
    respect to not raising Unix.Unix_error (Mauricio Fernandez, #316).
  * Improve diagnostics from build scripts (Tim Cuthbertson, #313, #314).

====== Additions ======

  * Announce Lwt_result, which was originally released as an experimental module
    in release 2.6.0 (Simon Cruanes, #320, #247).

===== 2.7.0 (2017-01-03) =====

====== General ======

  * Values of types a Lwt.t are now referred to as promises rather than threads
    (#300). The manual has not yet been updated.

====== Breaking ======

  * After this release, Lwt will switch to semantic versioning. Future breaking
    changes will first require deprecation, then a major version number increase
    (#293).
  * Lwt no longer supports OCaml 4.01 (#272).
  * Lwt_unix.fdatasync is no longer available on macOS. It was calling an
    undocumented system call on that system (#285, Jeremy Yallop).

====== Planned to break in 3.0.0 ======

  * APIs in this category have deprecation messages attached. The messages will
    be displayed if you recompile your code, and can also be seen in #308.
  * Lwt_engine.libev will have an argument for selecting the libev back end
    (#269, #294, Jeremy Yallop).
  * Lwt_io.establish_server will be replaced by a version that makes it
    difficult to leak file descriptors (#258, #260).
  * Lwt_io.shutdown_server will evaluate to a promise, which indicates when the
    close operation completes (#259).
  * Lwt_unix.bind will evaluate to a promise, since bind can block for Unix
    domain sockets (#296, requested David Sheets).
  * ocamlfind packages lwt.react, lwt.ssl, and lwt.glib will be replaced by the
    new lwt_react, lwt_ssl, and lwt_glib. These are now distributed in new OPAM
    packages with the same names, separately from OPAM package lwt (#301).

====== Additions ======

  * Lwt_unix.readv and Lwt_unix.writev - zero-copy scatter/gather I/O
    (#291, #299).
  * ?fail_on_error argument for Lwt_log.load_rules (#306, Daniil Baturin).
  * Lwt_log.level_of_string (#306, Daniil Baturin).

====== Changes ======

  * Lwt_stream.of_list, Lwt_stream.of_array, Lwt_stream.of_string now
    immediately push all elements into the created streams
    (#239, Spiros Eliopoulos).

====== Deprecations ======

  * Lwt_stream.map_exn in favor of Lwt_stream.wrap_exn, which uses OCaml's
    standard result type (#295).

====== Bugs fixed ======

  * Ungraceful failure if directory handle used after Lwt_unix.closedir (#292).
  * Buffer overflow in Lwt_unix.readdir and Lwt_unix.readdir_n (#292).
  * Unnecessary allocations in Lwt_unix.readdir_n (#292, found Jeremly Yallop).

====== Miscellaneous ======

  * Annotate existing deprecations with [@@ocaml.deprecated ...] (5737f5b).
  * Improvements to the examples (#288, Rich Neswold).
  * Documentation fixes, including by Rich Neswold.
  * New tests and various minor internal improvements.
  * Run tests in CI with all OCaml warnings enabled (dadb926).
  * Much cleaner build output.
  * Add scratch/ directory for local use by developers.

===== 2.6.0 (2016-10-27) =====

====== Additions ======

  * Lwt_stream.closed and Lwt_stream.is_closed (#223, Spiros Eliopoulos).
  * Lwt_switch.with_switch (#256, Thomas Leonard).
  * Define 'a Lwt.result as ('a, exn) result (#247, Simon Cruanes).
  * Lwt_condition.broadcast_exn (#241, Nicolas Ojeda Bar).
  * Lwt_unix.utimes (#193).

====== Bugfixes ======

  * Memory leak in Lwt_unix.readdir_n (#229, diagnosed Thomas Leonard).
  * Memory leak in Lwt.protected (#56, #181, reported @ygrek, Mauricio
    Fernandez).
  * Lwt_switch.turn_off hook exception handling (995b704).
  * Handling of ENOTCONN when channels passed to handler of
    Lwt_io.establish_server are closed (95fb431).
  * Duplicate exceptions on implicit close in Lwt_io.with_connection (b1afe45).
  * Deadlock in Lwt_main.at_exit (#48, #114, reported Jérôme Vouillon, Vincent
    Bernardoff).
  * Performance of Lwt_preemptive.detach (#218, #219, Mauricio Fernandez).
  * Bad hash functions for libev loops (#146, reported Mark Christiaens).
  * Hash of uninitialized data in Lwt_io (#217, reported Jeremy Yallop).
  * Update log sections after Lwt_log.load_rules (#188, reported @rand00).
  * Print three digits for milliseconds in Lwt_log (#264, Fabian Hemmer).
  * Do not truncate Unix job notification ids in C (#277, diagnosed
    @stijn-devriendt).

====== Deprecations ======

  * Lwt_stream.on_termination: bind on Lwt_stream.closed instead.
  * Lwt.make_value, Lwt.make_error: use result's Ok and Error constructors.
  * Lwt_pqueue, Lwt_sequence: use min-heaps and linked lists from another
    library (#135).
  * Pa_lwt, Pa_lwt_log: use Ppx_lwt.

====== Miscellaneous ======

  * Update examples to use PPX syntax instead of Camlp4 (#108, Peter Zotov).
  * Set up Travis, AppVeyor for testing on Linux, OS X, Cygwin, and MinGW. MSVC
    also planned.
  * Large amount of local documentation fixes (Hezekiah Carty, Etienne Millon,
    Leo Wzukw, Sebastien Mondet, reports by others).
  * A bunch of new tests.

===== 2.5.2 (2016-04-25) =====

  * Fix compatibility for 4.03 (#227)
  * Various documentation fixes (#199,#200,#210)
  * Improve wildcard detection in the ppx (#198)
  * Fix Lwt_stream: bounded_push#close wake the reader (#201)
  * Fix infinite loop with Lwt_stream.choose (#214)
  * Fix laziness failure with Lwt_io.common#close (#207)

===== 2.5.1 (2015-12-07) =====

  * Lwt_stream.on_terminate -> Lwt_stream.on_termination
  * Lwt_unix: handle O_CLOEXEC
  * Lwt_log: add OSX syslog path
  * Ppx: Improve lwt%match, improve catchall detection
  * Add Lwt_unix.file_exists and Lwt_unix.Large_file.file_exists
  * Build fixes

===== 2.5.0 (2015-07-03) =====

  * API CHANGE: Functions in Lwt_io that were previously using a
    ~buffer_size argument now takes a ~buffer argument.
  * Accept ?buffer argument in Lwt_ssl.{in,out}_channel_of_descr.
  * Use newer Ssl bigarray read/write functionality to avoid
    allocation in Lwt_ssl.
  * Fix non-reentrant function calls (#136)
  * IPv4 multicast support.
  * Add support for if%lwt in ppx extension.
  * Add Lwt.return_some.
  * Disable log syntax extension by default in ppx.
    Give [-log] as ppx argument to enable it.
  * Nanosecond precision for Lwt_unix.stat.
  * Minor fixes + documentation improvements.

===== 2.4.8 (2015-03-11) =====

  * Fix compilation under Windows (#117, #129)
  * Fix Lwt_engine.on_timer (#121)
  * Add Lwt_log_core.reset_rules (#123)
  * Fixed typos in the documentation (#119, #131)

===== 2.4.7 (2015-01-06) =====

  * camlp4 is now optional.
  * Add safe_string compliance except for Lwt_ssl (need ocaml-ssl fix).
  * Add Lwt.Infix module to open instead of Lwt to have (>>=), etc.
  * Add Lwt_list.filter_map_{s,p} functions.
  * Add Lwt.fail_{with,invalid_arg} functions.
  * Improved Android support.
  * Remove deprecated lwt.text and lwt.top libraries.
  * Remove deprecated Lwt_signal and Lwt_event modules from
    lwt.react.
  * Fix #111: try_lwt wrongly warns about unused match case.
  * Fix #96: Fix Lwt_react.S.limit and Lwt_react.E.limit.
  * Fix #91: Workaround to fix compilation on OSX.

===== 2.4.6 (2014-10-12) =====

  * Add a ppx syntax extension
  * Add a ?fd argument to
    Lwt_io.{open_connection,with_connection,establish_server}.
  * Fix stub for getaddrinfo and getprotobyname
  * Windows fix: don't throw an exception in the notification handler
    if we're shutting down
  * Fix include file search in ./configure
  * ./configure fixes for windows
  * Fix: use sys_exit instead of exit when Unix.execv fails

===== 2.4.5 (2014-04-21) =====

  * Lwt_ssl: expand API to allow setting socket options with Ssl
    functions
  * fix for camlp4 trunk
  * support for React 1.0.0
  * add Lwt_sequence.find_node_* functions
  * Lwt_log: get backtrace early to overcome exns in
    Printexc.to_string
  * fix potential deadlock in lwt_unix_recv_notifications
  * lwt.glib fixes:
    - handle HUP
    - fix for BSD/OSX
  * do not raise an exception in Lwt_log if argv[0] is blank

===== 2.4.4 (2013-10-22) =====

  * add Android support
  * fix issues in stubs for Lwt_unix jobs
  * fix compatibility issue with OCaml 4.01
  * fix the stub for ev_timer_init
  * add Lwt.log containing Lwt_log_core, the Unix-free part of Lwt_log
  * add Lwt_ssl.get_fd
  * fix stdout/stderr redirections in Lwt_daemon.daemonize
  * add Lwt_list.{map,iter}i{_s,_p}

===== 2.4.3 (2012-12-27) =====

  * fix Lwt_ssl.{in,out}_channel_of_descr: shutdown and close the
    socket when the channel is closed

===== 2.4.2 (2012-09-28) =====

  * fix the stub for Lwt_unix.readdir
  * change the default method for Lwt_glib.install
    (use the glib main loop by default: more portable)
  * ignore invalid file descriptors returned by glib
    (like the emulation of select in glib does)
  * use environment variables in discover.ml
    - use LIBRARY_PATH and C_INCLUDE_PATH for searching headers
    - allow to pass flags for a library in <LIB>_CLFAGS and <LIB>_LIBS
  * add Lwt_unix.on_signal_full

===== 2.4.1 (2012-08-22) =====

  * Add Lwt_stream.on_terminate
  * Fix Lwt_gc
  * Fix stubs for get_credentials on *BSD

===== 2.4.0 (2012-07-16) =====

  * Reimplement Lwt_stream
    - much simpler and more efficient
    - do not use Weak
    - add bounded push streams
  * Add Lwt.async
  * Add Lwt_preemptive.run_in_main
  * Implement Lwt_unix.get_credentials on MacOS X/OpenBSD
  * Ensure that on_cancel functions are executed first
  * Better implementation of Lwt.cancel with more tests
  * Simplify the API for unix jobs
  * Better handling of the master lock in libev stubs
  * Windows fixes/updates:
    - pass -lws2_32 instead of ws2_32.lib if building with mingw
    - fix a bug causing Lwt_unix.read/write to block when a socket
      is not readable/writable
    - port Lwt_process and Lwt_unix.system to Windows
  * Compatibility with OCaml 4.00:
    - add O_SHARE_DELETE to Lwt_unix.open_flag
    - add -package compiler-libs.toplevel for files using Toploop
  * Do not use module Sys for signal handling to avoid
    OCaml code to be called in a C thread
  * Fix Lwt_unix.wrap_syscall: try instead of Lwt.catch
  * Fix a dead-lock between lwt_unix_send_notification
    and lwt_unix_recv_notifications
  * Fix #277: add a function to return the Ssl.socket of a Lwt_ssl.socket
  * Fix problems with C libraries detection/linking

===== 2.3.2 (2011-11-04) =====

  * Add location informations in logs:
    ** allow loggers to get the current location through local storage
    ** pass current location to logging functions
    ** pass the current location with the syntax extension
  * Add Lwt.on_termination
  * Add Lwt_unix.reinstall_signal_handler
  * Add Lwt_io.flush_all
  * Add assert_lwt keyword to the syntax extension
  * Add Lwt.wrap
  * Add Lwt_glib.iter and Lwt_glib.wakeup
  * OCaml 3.13 ready
  * Allow to compile without libev support
  * Fix bugs in Lwt_io
  * Better handling of forks
  * Fix many problems on Windows

===== 2.3.1 (2011-07-13) =====

  * Fix building of documentation when using the tarball
  * Add Lwt_unix.fsync and Lwt_unix.fdatasync
  * Fix the stubs for Lwt_unix.send_msg when fd-passing is not
    available
  * Add -lwt-sequence-strict option to the syntax extension
  * Use a custom PRNG state for Lwt.choose and Lwt.pick
  * Fix a display glitch when starting the toplevel
  * Add Lwt_unix.fork which should now be used when one want to use
    Lwt in the child process
  * Better implementation of Lwt_unix.readlink and
    Lwt_unix.gethostbyname, which fixes compilation on Hurd
  * Add Lwt.wakeup_later and Lwt.wakeup_later_exn to be used when one
    need to do lot of nested wakeup, which fixes a buffer overflow in
    Lwt_mutex
  * Fix Lwt_unix.abort and Lwt_unix.close (threads was never wakeup)
  * Fix Lwt_throttle for correct timings
  * Fix subtle use of cancel

===== 2.3.0 (2011-04-12) =====

  * Add an extensible system of engines to:
    ** allow the user to replace libev by another event system, such
       as select
    ** allow easier integration of external libraries supporting
       asynchronous operations
  * Lots of improvements for Windows:
    ** use the OCaml select instead of libev by default on Windows
    ** make asynchronous operations on non-socket file descriptors
       such as pipes to work
    ** make glib integration to work
  * Better use of engines in Lwt_unix: now events are cached to minimize
    the amount of calls to epoll_ctl
  * Use an eventfd when possible for notifications for faster delivery
  * Add modules:
    ** Lwt_sys: allow to test availability of extra features
    ** Lwt_react: replace Lwt_event and Lwt_signal
  * Allow to configure logging rules at runtime in Lwt_log
  * Add match_lwt and while_lwt to the syntax extension
  * Fixes:
    ** syntax extension: handle "lwt ... = ... in ..." at toplevel
    ** make the notification system fork-proof
    ** fix an issue with stubs not raising correctly exceptions

===== 2.2.1 (2011-01-26) =====

  * Better interaction with Js_of_OCaml.
  * Add functions {{{Lwt.register_pause_notifier}}} and {{{Lwt.paused_count}}}.

===== 2.2.0 (2010-12-13) =====

  * Bugfixes:
    ** Fix a bug with cancellable threads causing {{{Canceled}}}
       exceptions to be raised randomly
    ** Fix a fd-leak in Lwt_io.open_connection
  * {{{Lwt_unix}}} now use libev instead of select
  * Add thread local storage support to {{{Lwt}}}
  * Add backtrace support to {{{Lwt}}}. Now {{{Lwt}}} exceptions can
    be recorded by using the syntax extension with the {{{-lwt-debug}}}
    command line switch.
  * Allow blocking system calls to be executed in parallels
  * Change the type of many functions of {{{Lwt_unix}}}, which now
    return a {{{Lwt}}} thread
  * Add functions {{{Lwt_unix.readable}}} and {{{Lwt_unix.writable}}}
  * Add function {{{Lwt_io.is_busy}}}
  * Add functions {{{Lwt_event.delay}}} and {{{Lwt_signal.delay}}}
  * Add function {{{Lwt_term.render_update}}}
  * Add function {{{Lwt_ssl.embed_socket}}}
  * Add module {{{Lwt_bytes}}} defining operations on bigarrays
    instead of strings
  * Use bigarrays in Lwt_io instead of strings for the internal buffer.
    Lwt_io.make now takes a function that uses a bigarray.
  * Add module {{{Lwt_switch}}}

===== 2.1.1 (2010-06-13) =====

  * Many bugfixes, including:
    ** buggy behaviour of cancellable threads
    ** file descriptor leakage in {{{Lwt_unix.accept_n}}}
  * Add {{{Lwt.nchoose}}} and {{{Lwt.npick}}}
  * Use {{{set_close_on_exec}}} for fds created by {{{Lwt_log}}}
  * Better implementation of lwtized react functions

===== 2.1.0 (2010-04-19) =====

  * Rename {{{Lwt.select}}} to {{{Lwt.pick}}}
  * Removing module {{{Lwt_monitor}}} in favour of {{{Lwt_mutex}}} and
    new module {{{Lwt_condition}}}
  * More react helpers:
    ** {{{Lwt_event.next}}}
    ** {{{Lwt_event.limit}}} and {{{Lwt_signal.limit}}}
    ** {{{Lwt_event.from}}}
  * Adding function {{{Lwt_main.fast_yield}}}
  * Adding unit tests
  * Optimisation of {{{Lwt}}}
  * Adding module {{{Lwt_log}}} for logging
  * Adding a camlp4 filter for remmoving logging statement or inlining
    tests
  * Adding module {{{Lwt_daemon}}}
  * Adding function {{{Lwt_unix.recv_msg}}} and {{{Lwt_unix.send_msg}}}
  * Adding function {{{Lwt_unix.wait4}}}
  * Adding function {{{Lwt_io.establish_server}}}
  * Adding module {{{Lwt_list}}}
  * Enhancement in {{{Lwt_process}}}, it now support redirections and
    timeouts
  * Allow to use {{{select}}} on arbitrary high file descriptors
  * More commands and features in {{{Lwt_read_line}}}:
    ** Handle "undo" command
    ** New controllable read-lines instances
    ** More edition commands
    ** Completion as you type
    ** Backward search
  * Enhancement in {{{Lwt_term}}}: more drawing functions and allow to
    put the terminal into drawing mode
  * Optimisation of {{{Lwt_stream}}}
  * Optimisation of {{{Lwt_io.write_char}}} and {{{Lwt_io.read_char}}}
  * Bugfix of {{{Lwt_stream}}}: two parallel {{{Lwt_stream.get}}}
    returned the same value
  * Bugfix in {{{Lwt_unix.connect}}}: it returned immediately on EINPROGRESS
  * Bugfixes in {{{Lwt_glib}}}: file descriptors were not monitored correctly

===== 2.0.0 (2009-10-15) =====

  * Adding modules:
    ** {{{Lwt_stream}}}: lwt-aware version of the {{{Stream}}} module
    ** {{{Lwt_gc}}} for using {{{finalise}}} without
       {{{Lwt_unix.run}}}
    ** {{{Lwt_io}}}: a new implementation of buffered channels with
       more features and better handling of concurrent access
    ** {{{Lwt_text}}}: implementation of text channels
    ** {{{Lwt_process}}}: helpers to spawn processes and communicate
       with them
    ** {{{Lwt_main}}} for abstracting the main loop and allowing
       replacement by a custom main loop
    ** {{{Lwt_glib}}} for integration into the glib main event loop
    ** {{{Lwt_term}}} for interaction with the terminal
    ** {{{Lwt_read_line}}} for interactive user input
    ** {{{Lwt_monitor}}}, {{{Lwt_mvar}}}: combined locks for
       synchronization with conditional variables for notification
    ** {{{Lwt_throttle}}} for limiting rate of execution
       (e.g. for authentication procedure)
    ** {{{Lwt_sequence}}}: mutable sequence of elements
    ** {{{Lwt_event}}}, {{{Lwt_signal}}}: helpers for reactive
       programming with lwt
  * Adding a syntax extension {{{pa_lwt}}}:
    ** handles anonymous bind {{{a >> b}}}
    ** adds syntactic sugar for catching errors (ticket #6)
    ** adds syntactic sugar for parallel let-binding construction
    ** adds syntactic sugar for for-like loops
  * Top-level integration:
    ** threads can runs while reading user input
    ** line editing support
  * New enhanced OCaml toplevel with some basic completion features
  * Adding C stubs to reimplement {{{Unix.read}}} and {{{Unix.write}}}
    with assumption of non-blocking behaviour
  * Adding more functions/helpers in {{{Lwt}}}
  * Fixing memory leaks in {{{Lwt.choose}}}
  * Bugfix in {{{Lwt_chan.close_*}}} (ticket #66)
  * Separate the type of threads (covariant) from the type of thread
    wakeners (contravariant); the type of many functions related to
    {{{Lwt.wait}}} has been changed
  * Add cancelable threads
  * Unix-dependent part is now put in its own archive and findlib
    package.

===== 1.1.0 (2008-06-25) =====

  * Adding module {{{Lwt_pool}}} for creating pools (for example pools
    of connections)
  * Adding a few functions in {{{Lwt_chan}}}
  * Fixing bugs in {{{Lwt_util.map_serial}}} and
    {{{Lwt_util.iter_serial}}}
  * Putting {{{Lwt_preemptive}}}, {{{Lwt_lib}}} and {{{Lwt_ssl}}} in
    separate libraries and findlib subpackages so that lwt.cma depends
    only on unix.cma.

===== 1.0.0 (and before) =====

  * See Ocsigen changelog