package lwt

  1. Overview
  2. Docs
Promises and event-driven I/O

Install

Dune Dependency

Authors

Maintainers

Sources

5.5.0.tar.gz
md5=94272fac89c5bf21a89c102b8a8f35a5
sha512=8951b94555e930634375816d71815b9d85daad6ffb7dab24864661504d11be26575ab0b237196c54693efa372a9b69cdc1d5068a20a250dc0bbb4a3c03c5fda1

Description

A promise is a value that may become determined in the future.

Lwt provides typed, composable promises. Promises that are resolved by I/O are resolved by Lwt in parallel.

Meanwhile, OCaml code, including code creating and waiting on promises, runs in a single thread by default. This reduces the need for locks or other synchronization primitives. Code can be run in parallel on an opt-in basis.

Published: 26 Nov 2021

README

Lwt

Lwt is a concurrent programming library for OCaml. It provides a single data type: the promise, which is a value that will become determined in the future. Creating a promise spawns a computation. When that computation is I/O, Lwt runs it in parallel with your OCaml code.

OCaml code, including creating and waiting on promises, is run in a single thread by default, so you don't have to worry about locking or preemption. You can detach code to be run in separate threads on an opt-in basis.

Here is a simplistic Lwt program which requests the Google front page, and fails if the request is not completed in five seconds:

open Lwt.Syntax

let () =
  let request =
    let* addresses = Lwt_unix.getaddrinfo "google.com" "80" [] in
    let google = Lwt_unix.((List.hd addresses).ai_addr) in

    Lwt_io.(with_connection google (fun (incoming, outgoing) ->
      let* () = write outgoing "GET / HTTP/1.1\r\n" in
      let* () = write outgoing "Connection: close\r\n\r\n" in
      let* response = read incoming in
      Lwt.return (Some response)))
  in

  let timeout =
    let* () = Lwt_unix.sleep 5. in
    Lwt.return None
  in

  match Lwt_main.run (Lwt.pick [request; timeout]) with
  | Some response -> print_string response
  | None -> prerr_endline "Request timed out"; exit 1

(* ocamlfind opt -package lwt.unix -linkpkg example.ml && ./a.out *)

In the program, functions such as Lwt_io.write create promises. The let* ... in construct is used to wait for a promise to become determined; the code after in is scheduled to run in a "callback." Lwt.pick races promises against each other, and behaves as the first one to complete. Lwt_main.run forces the whole promise-computation network to be executed. All the visible OCaml code is run in a single thread, but Lwt internally uses a combination of worker threads and non-blocking file descriptors to resolve in parallel the promises that do I/O.


Overview

Lwt compiles to native code on Linux, macOS, Windows, and other systems. It's also routinely compiled to JavaScript for the front end and Node by js_of_ocaml.

In Lwt,

  • The core library Lwt provides promises...

  • ...and a few pure-OCaml helpers, such as promise-friendly mutexes, condition variables, and mvars.

  • There is a big Unix binding, Lwt_unix that binds almost every Unix system call. A higher-level module Lwt_io provides nice I/O channels.

  • Lwt_process is for subprocess handling.

  • Lwt_preemptive spawns system threads.

  • The PPX syntax allows using all of the above without going crazy!

  • There are also some other helpers, such as Lwt_react for reactive programming. See the table of contents on the linked manual pages!


Installing

  1. Use your system package manager to install a development libev package. It is often called libev-dev or libev-devel.

  2. opam install conf-libev lwt


Documentation

We are currently working on improving the Lwt documentation (drastically; we are rewriting the manual). In the meantime:

  • The current manual can be found here.

  • Mirage has a nicely-written Lwt tutorial.

  • An example of a simple server written in Lwt.

  • Concurrent Programming with Lwt is a nice source of Lwt examples. They are translations of code from the excellent Real World OCaml, but are just as useful if you are not reading the book.

Note: much of the current manual refers to 'a Lwt.t as "lightweight threads" or just "threads." This will be fixed in the new manual. 'a Lwt.t is a promise, and has nothing to do with system or preemptive threads.


Contact

Open an issue, visit Discord chat, ask on discuss.ocaml.org, or on Stack Overflow.

Release announcements are made in /r/ocaml, and on discuss.ocaml.org. Watching the repo for "Releases only" is also an option.


Contributing

  • CONTRIBUTING.md contains tips for working on the code, such as how to check the code out, how review works, etc. There is also a high-level outline of the code base.

  • Ask us anything, whether it's about working on Lwt, or any question at all about it :)

  • The documentation always needs proofreading and fixes.

  • You are welcome to pick up any other issue, review a PR, add your opinion, etc.

  • Any feedback is welcome, including how to make contributing easier!


Libraries to use with Lwt

Dependencies (10)

  1. seq
  2. result
  3. ocplib-endian
  4. ocaml-syntax-shims
  5. ocaml >= "4.08.0"
  6. ocaml (>= "4.02.0" & "os" != "win32 " | >= "4.06.0") & < "5.0"
  7. mmap >= "1.1.0" & "os" != "win32"
  8. dune-configurator
  9. dune >= "1.8.0"
  10. cppo build & >= "1.1.0"

Dev Dependencies (1)

  1. ocamlfind dev & >= "1.7.3-1"

  1. 0install >= "2.15.1"
  2. aches-lwt
  3. albatross
  4. alcotest-lwt
  5. alcotest-mirage
  6. ambient-context-lwt
  7. amqp-client >= "0.9.0" & < "1.0.2" | >= "1.1.0"
  8. amqp-client-lwt >= "2.0.1"
  9. angstrom-lwt-unix
  10. anthill
  11. anycache-lwt
  12. arakoon < "1.8.6" | >= "1.8.8"
  13. archi-lwt
  14. arp >= "2.3.1"
  15. arp-mirage >= "2.2.1"
  16. awa-lwt
  17. awa-mirage
  18. aws-lwt
  19. aws-s3-lwt
  20. awsm-lwt
  21. azure-cosmos-db
  22. baardskeerder
  23. balancer
  24. bap < "1.0.0"
  25. bap-server < "0.2.0"
  26. bastet_lwt
  27. bimage-lwt
  28. biocaml = "0.4.0"
  29. bistro >= "0.4.0"
  30. brozip
  31. builder
  32. builder-web
  33. bun >= "0.3.3"
  34. c3
  35. calculon
  36. caldav
  37. camltc = "0.9.5" | >= "0.9.7.0"
  38. canary
  39. capnp-rpc-lwt < "1.2.3"
  40. capnp-rpc-unix >= "0.9.0" & < "1.2.3"
  41. caqti-lwt >= "0.11.0"
  42. caqti-mirage
  43. carton
  44. carton-git
  45. carton-lwt
  46. cf-lwt
  47. chamelon
  48. chamelon-unix
  49. chamo >= "3.0"
  50. channel
  51. charrua-client >= "1.3.0"
  52. charrua-client-lwt
  53. charrua-client-mirage
  54. charrua-core < "0.3"
  55. charrua-unix >= "0.3" & != "0.10"
  56. clz
  57. cmdtui-lambda-term
  58. coclobas
  59. cohttp-curl-lwt
  60. cohttp-lwt
  61. cohttp-lwt-jsoo
  62. cohttp-lwt-unix >= "1.1.1"
  63. cohttp-lwt-unix-nossl
  64. cohttp-lwt-unix-ssl
  65. cohttp-mirage
  66. cohttp-server-lwt-unix
  67. comby
  68. comby-semantic
  69. conan-lwt
  70. conduit-lwt
  71. conduit-lwt-unix
  72. cowabloga >= "0.2.2"
  73. crunch >= "2.0.0"
  74. cstruct-lwt
  75. csv-lwt
  76. csvprovider
  77. ctypes >= "0.15.0" & < "0.21.1"
  78. ctypes-foreign >= "0.21.1"
  79. current < "0.6.4"
  80. current_docker < "0.6.4"
  81. current_examples < "0.6.4"
  82. current_git < "0.6.4"
  83. current_github < "0.6.4"
  84. current_gitlab < "0.6.4"
  85. current_ocluster < "0.2"
  86. current_rpc >= "0.4" & < "0.6.4"
  87. current_slack < "0.6.4"
  88. current_web < "0.6.4"
  89. DkSDKFFIOCaml_Std
  90. dap
  91. data-encoding < "0.1.1"
  92. datakit
  93. datakit-bridge-github
  94. datakit-bridge-local-git
  95. datakit-ci
  96. datakit-client >= "0.11.0"
  97. datakit-github
  98. datakit-server
  99. devkit >= "1.2"
  100. dht < "0.2.0"
  101. distributed-lwt
  102. dkim-mirage
  103. dlm
  104. dns >= "0.19.1" & < "0.20.1"
  105. dns-certify
  106. dns-cli >= "4.6.3"
  107. dns-client < "7.0.0"
  108. dns-client-lwt
  109. dns-client-mirage
  110. dns-forward >= "0.9.0"
  111. dns-forward-lwt-unix
  112. dns-lwt
  113. dns-mirage
  114. dns-resolver
  115. dns-server
  116. dns-stub
  117. dnssd
  118. docker_hub
  119. docteur
  120. docteur-solo5
  121. docteur-unix
  122. doi2bib
  123. dream
  124. dream-httpaf
  125. dream-pure
  126. dream-serve
  127. dropbox
  128. dune-rpc-lwt
  129. dune_watch
  130. earlybird
  131. elasticsearch-cli >= "0.4"
  132. equinoxe
  133. eris-lwt
  134. ethernet
  135. ez_api
  136. ezcurl-lwt
  137. ezirmin
  138. ezjs_min < "0.2"
  139. ezjsonm >= "0.4.2" & < "0.5.0"
  140. ezjsonm-lwt
  141. ezresto
  142. ezresto-directory >= "0.5"
  143. faraday-lwt
  144. faraday-lwt-unix >= "0.6.0"
  145. fat-filesystem >= "0.12.0"
  146. fiber-lwt
  147. flowtype >= "0.72.0"
  148. frenetic < "2.0.0"
  149. fsevents-lwt
  150. fswatch_lwt
  151. fuseau-lwt
  152. gamepad
  153. gdb
  154. gdbprofiler >= "0.3"
  155. git != "1.4.3" & != "1.7.2"
  156. git-cohttp
  157. git-cohttp-mirage
  158. git-cohttp-unix
  159. git-mirage >= "3.0.0"
  160. git-paf
  161. git-unix = "1.11.1" | >= "3.0.0" & < "3.10.0"
  162. github
  163. github-hooks < "0.2.0" | >= "0.4.0"
  164. github-unix >= "4.4.0"
  165. gitlab-unix
  166. gluten-lwt
  167. gluten-lwt-unix < "0.4.0"
  168. gluten-mirage < "0.4.0"
  169. graphql-lwt
  170. gremlin
  171. grpc-lwt
  172. gufo
  173. h2-lwt
  174. h2-lwt-unix < "0.10.0"
  175. h2-mirage
  176. happy-eyeballs-lwt
  177. happy-eyeballs-mirage
  178. hardcaml < "1.1.0"
  179. hardcaml-examples >= "0.3.0"
  180. hardcaml-framework
  181. hiredis != "0.4"
  182. hl_yaml
  183. hockmd
  184. horned_worm < "0.3.1"
  185. http-lwt-client
  186. http-mirage-client
  187. http-multipart-formdata >= "2.0.0" & < "3.0.0"
  188. http2https
  189. httpaf-lwt-unix
  190. hvsock >= "1.0.2"
  191. i3ipc >= "0.1.4"
  192. imaplet-lwt
  193. influxdb-lwt
  194. inotify >= "2.4"
  195. inquire < "0.3.0"
  196. interface-prime-lwt
  197. iocaml < "0.4.6"
  198. iocaml-kernel >= "0.4.3" & < "0.4.6"
  199. iocamljs-kernel
  200. ip2location
  201. ip2locationio
  202. ipv6-multicast-lwt
  203. irc-client-lwt
  204. irc-client-lwt-ssl
  205. irc-client-tls
  206. irmin < "0.9.6" | = "0.9.10" | >= "0.11.0"
  207. irmin-bench
  208. irmin-chunk
  209. irmin-cli
  210. irmin-containers
  211. irmin-fs >= "2.3.0"
  212. irmin-git >= "2.3.0"
  213. irmin-graphql >= "2.3.0"
  214. irmin-http >= "2.3.0"
  215. irmin-indexeddb
  216. irmin-layers
  217. irmin-mem >= "2.3.0"
  218. irmin-mirage-git >= "2.3.0"
  219. irmin-mirage-graphql >= "2.3.0"
  220. irmin-pack
  221. irmin-server
  222. irmin-test >= "2.3.0"
  223. irmin-unix >= "2.3.0"
  224. irmin-watcher >= "0.3.0"
  225. jerboa
  226. jitsu
  227. joolog
  228. jose < "0.9.0"
  229. js_of_ocaml < "2.5"
  230. js_of_ocaml-lwt >= "3.5.0"
  231. jsoo_broadcastchannel
  232. jsoo_router
  233. jsoo_storage
  234. jupyter >= "2.3.0"
  235. jupyter-kernel >= "0.4"
  236. kafka >= "0.3" & < "0.5"
  237. kafka_lwt
  238. kappa-library
  239. ke >= "0.5"
  240. ketrew >= "3.2.0"
  241. kinetic-client < "0.0.3" | >= "0.0.9"
  242. kubecaml
  243. lablqml < "0.6"
  244. lambda-runtime
  245. lambda-term >= "1.13"
  246. lambda_streams_lwt
  247. launchd
  248. ldp
  249. learn-ocaml >= "0.13.0"
  250. learn-ocaml-client >= "0.13.0"
  251. letsencrypt
  252. letsencrypt-app
  253. letsencrypt-dns
  254. letters
  255. libres3
  256. links != "0.9"
  257. linol-lwt
  258. llama
  259. lru_cache < "v0.16.0"
  260. lwt-binio < "0.2.0"
  261. lwt-canceler
  262. lwt-dllist
  263. lwt-exit
  264. lwt-parallel >= "1.0.0"
  265. lwt-pipe
  266. lwt-pipeline
  267. lwt-watcher
  268. lwt-zmq < "1.0.0"
  269. lwt_camlp4
  270. lwt_domain < "0.3.0"
  271. lwt_eio < "0.4"
  272. lwt_glib >= "1.0.1"
  273. lwt_log >= "1.1.0"
  274. lwt_ppx
  275. lwt_ppx_let
  276. lwt_react >= "1.0.1"
  277. lwt_ssl >= "1.0.1"
  278. mariadb < "0.5.1"
  279. markup = "0.7.6"
  280. markup-lwt
  281. mdx
  282. mechaml
  283. memtrace-mirage
  284. metrics-influx
  285. metrics-lwt
  286. metrics-mirage
  287. metrics-unix
  288. mimic
  289. mindstorm-lwt
  290. mirage >= "0.4.1" & != "0.6.1" & < "0.8.0" | >= "0.10.0" & < "2.7.0"
  291. mirage-block < "1.0.0" | >= "2.0.0"
  292. mirage-block-ccm
  293. mirage-block-combinators
  294. mirage-block-lwt
  295. mirage-block-ramdisk
  296. mirage-block-solo5
  297. mirage-block-unix < "2.3.0" | = "2.8.2" | >= "2.13.0"
  298. mirage-block-xen
  299. mirage-bootvar-solo5 >= "0.2.0"
  300. mirage-bootvar-unix
  301. mirage-bootvar-xen >= "0.4.0"
  302. mirage-channel >= "4.0.0"
  303. mirage-channel-lwt
  304. mirage-clock-freestanding < "3.0.0"
  305. mirage-clock-lwt
  306. mirage-clock-unix >= "1.3.0" & < "3.0.0"
  307. mirage-console >= "3.0.0"
  308. mirage-console-lwt
  309. mirage-console-solo5 >= "0.2.0"
  310. mirage-console-unix >= "2.2.1"
  311. mirage-console-xen >= "5.0.0"
  312. mirage-console-xen-backend
  313. mirage-console-xen-cli
  314. mirage-crypto-entropy
  315. mirage-crypto-rng >= "0.7.0" & < "0.11.0"
  316. mirage-crypto-rng-lwt
  317. mirage-crypto-rng-mirage >= "0.8.8"
  318. mirage-device >= "2.0.0"
  319. mirage-dns < "3.0.0"
  320. mirage-entropy
  321. mirage-flow >= "1.0.3" & < "1.2.0" | >= "2.0.0"
  322. mirage-flow-combinators
  323. mirage-flow-lwt
  324. mirage-flow-rawlink
  325. mirage-flow-unix >= "1.3.0"
  326. mirage-fs >= "3.0.0"
  327. mirage-fs-lwt
  328. mirage-fs-unix < "1.1.1" | >= "1.3.0"
  329. mirage-http
  330. mirage-http-unix
  331. mirage-http-xen
  332. mirage-kv >= "3.0.0"
  333. mirage-kv-lwt
  334. mirage-kv-unix
  335. mirage-logs != "0.3.0"
  336. mirage-nat < "3.0.0"
  337. mirage-net >= "3.0.1"
  338. mirage-net-fd
  339. mirage-net-lwt
  340. mirage-net-macosx
  341. mirage-net-solo5
  342. mirage-net-unix >= "2.2.0"
  343. mirage-net-xen
  344. mirage-os-shim >= "3.0.0"
  345. mirage-profile
  346. mirage-protocols >= "4.0.0" & < "8.0.0"
  347. mirage-protocols-lwt
  348. mirage-qubes < "0.2" | >= "0.4"
  349. mirage-qubes-ipv4
  350. mirage-random-stdlib >= "0.1.0"
  351. mirage-runtime >= "3.7.0"
  352. mirage-solo5
  353. mirage-stack >= "2.0.0" & < "4.0.0"
  354. mirage-stack-lwt
  355. mirage-time >= "2.0.0"
  356. mirage-time-lwt
  357. mirage-time-unix
  358. mirage-types-lwt < "3.7.1"
  359. mirage-unix >= "3.0.0"
  360. mirage-vnetif
  361. mirage-vnetif-stack
  362. mirage-www >= "1.1.0"
  363. mirage-xen
  364. mirror
  365. monorobot
  366. mqtt >= "0.0.2"
  367. mrmime >= "0.5.0"
  368. multipart-form-data >= "0.2.0"
  369. multipart_form >= "0.2.0" & < "0.4.0"
  370. multipart_form-cohttp-lwt
  371. multipart_form-lwt
  372. mwt
  373. naboris
  374. nanomsg
  375. nbd = "2.1.1" | >= "4.0.3"
  376. nbd-tool
  377. nbd-unix
  378. netchannel
  379. nocrypto >= "0.5.4"
  380. nottui-lwt
  381. nproc
  382. nsq >= "0.4.0"
  383. obrowser
  384. obuilder < "0.5"
  385. obus >= "1.2.1"
  386. ocaml-variants >= "4.00.1+mirage-unix" & < "4.00.1+open-types"
  387. ocluster < "0.2"
  388. ocluster-api < "0.2"
  389. ocplib-concur
  390. ocplib-resto
  391. ocsigen-start >= "4.1.0" & < "4.7.0"
  392. ocsigenserver >= "2.10"
  393. ocsipersist
  394. ocsipersist-dbm
  395. ocsipersist-lib
  396. ocsipersist-pgsql
  397. ocsipersist-sqlite
  398. odoc >= "2.0.0" & < "2.1.0"
  399. oframl
  400. ojquery
  401. ojs-base
  402. ojs_base
  403. omigrate
  404. oneffs
  405. opam-compiler < "0.2.0"
  406. opam-sync-github-prs
  407. openflow < "0.2.0"
  408. opentelemetry-client-cohttp-lwt
  409. opentelemetry-cohttp-lwt >= "0.4"
  410. opentelemetry-lwt
  411. opium >= "0.11.0" & != "0.16.0"
  412. opium-graphql
  413. opium_kernel
  414. opomodoro
  415. order-i3-xfce
  416. ordma >= "0.0.3"
  417. osc-lwt
  418. oskel >= "0.3.0"
  419. ounit-lwt < "2.2.0"
  420. ounit2-lwt
  421. owork
  422. ox < "1.1.0"
  423. ozulip
  424. paf
  425. paf-cohttp
  426. pcap-format >= "0.3.3" & < "0.5.0"
  427. petrol
  428. pgx_lwt
  429. pgx_lwt_mirage
  430. pgx_lwt_unix < "2.0"
  431. piaf
  432. plebeia >= "2.0.0"
  433. plist-xml-lwt
  434. plotkicadsch >= "0.4.0"
  435. ppx_defer >= "0.4.0"
  436. ppx_deriving_rpc
  437. ppx_json_types
  438. ppx_netblob
  439. ppx_rapper_lwt
  440. ppx_sqlexpr
  441. proc-smaps
  442. prof_spacetime
  443. prometheus
  444. prometheus-app
  445. promise_jsoo_lwt
  446. protocol-9p >= "0.10.0"
  447. protocol-9p-unix
  448. qcow >= "0.8.1"
  449. qcow-format < "0.3"
  450. qcow-tool
  451. qfs = "0.5" | >= "0.7"
  452. quests
  453. rawlink >= "1.0" & < "2.1"
  454. rawlink-lwt
  455. rdf_json_ld < "1.0.0"
  456. rdf_lwt < "1.0.0"
  457. redis-lwt
  458. reparse-lwt
  459. reparse-lwt-unix
  460. resource-pooling >= "0.3.2"
  461. resp
  462. resp-mirage >= "0.10.0"
  463. resp-unix >= "0.10.0"
  464. resto
  465. resto-cohttp-client >= "0.4"
  466. resto-cohttp-self-serving-client
  467. resto-cohttp-server >= "0.4"
  468. resto-directory >= "0.4"
  469. riak
  470. ringo-lwt
  471. river
  472. rock
  473. rpc >= "1.5.1" & < "7.1.0"
  474. rpclib-js
  475. rpclib-lwt
  476. SZXX < "4.0.0"
  477. sanddb
  478. scgi
  479. sendmail-lwt
  480. serial
  481. session-cohttp-lwt
  482. session-cookie-lwt
  483. session-postgresql-lwt >= "0.4.1"
  484. sessions
  485. shared-block-ring < "2.3.0" | >= "3.0.0"
  486. shared-memory-ring >= "1.2.0" & < "2.0.0"
  487. shared-memory-ring-lwt
  488. sihl < "0.2.0"
  489. slack
  490. slacko
  491. socket-daemon < "0.3.0"
  492. spin < "0.8.0"
  493. spotify-web-api < "0.2.1"
  494. sqlexpr = "0.7.1" | >= "0.9.0"
  495. statsd-client
  496. stk
  497. stog >= "0.16.0" & < "1.0.0"
  498. syguslib-utils
  499. syndic >= "1.4" & < "1.6.0"
  500. tar-format >= "0.4.1"
  501. tar-mirage < "2.2.0"
  502. tar-unix
  503. tcpip >= "3.1.1" & < "3.4.1" | >= "4.1.0"
  504. teash
  505. telegraml
  506. terminus
  507. tezos-base >= "13.0" & < "15.0"
  508. tezos-clic >= "13.0" & < "15.0"
  509. tezos-crypto >= "13.0" & < "15.0"
  510. tezos-error-monad >= "8.0" & < "9.0" | >= "13.0" & < "15.0"
  511. tezos-lwt-result-stdlib >= "9.0" & < "15.0"
  512. tezos-p2p >= "11.0" & < "13.0"
  513. tezos-protocol-compiler >= "13.0"
  514. tezos-protocol-environment >= "13.0" & < "15.0"
  515. tezos-proxy-server
  516. tezos-stdlib < "15.0"
  517. tezos-stdlib-unix < "9.0" | >= "13.0" & < "15.0"
  518. tezos-test-helpers >= "12.0" & < "15.0"
  519. tezt < "3.0.0"
  520. tftp
  521. themoviedb
  522. tidy_email
  523. tls = "0.10.1" | >= "0.10.6" & < "0.16.0"
  524. tls-lwt < "0.17.4"
  525. tls-mirage
  526. transmission-rpc
  527. tube >= "4.3.0"
  528. tuntap >= "1.0.0" & < "1.7.0" | >= "2.0.0"
  529. typerex-lldb
  530. u2f
  531. uring
  532. uspf
  533. uspf-lwt
  534. utop >= "1.4.0"
  535. uwt >= "0.3.0"
  536. vchan >= "0.9.7" & < "2.0.0" | >= "2.0.3"
  537. vchan-unix
  538. vchan-xen
  539. vercel
  540. vhd-format >= "0.7.0" & < "0.8.0"
  541. vhd-format-lwt >= "0.12.0"
  542. vhd-tool < "0.12.0"
  543. vmnet >= "1.3.2"
  544. vpnkit >= "0.2.0"
  545. vue-jsoo < "0.3"
  546. wayland < "2.0"
  547. webauthn
  548. websocket < "2.3"
  549. xe-unikernel-upload
  550. xen-api-client < "0.9.14"
  551. xen-block-driver
  552. xen-evtchn < "1.0.6" | >= "2.0.0"
  553. xen-evtchn-unix
  554. xen-gnt >= "2.2.3"
  555. xenctrl < "0.9.29" | >= "0.9.32"
  556. xenstore >= "1.3.0"
  557. xenstore_transport >= "1.0.0"
  558. xentropyd
  559. yocaml_git
  560. yocaml_unix
  561. yurt < "0.3"
  562. zmq-lwt

Conflicts (1)

  1. ocaml-variants = "4.02.1+BER"