src/core/packages/event.sgl

1;;; Asynchronous event notification.

2;;;

3;;; libevent lands in its own module rather than beside ncurses in

4;;; (core packages terminal), even though tmux is the only thing in the channel

5;;; that wants it today. Two reasons, and the second is the one that matters:

6;;;

7;;; * it follows the channel's existing shape. compression/, databases/,

8;;; parsing/ and xml/ are each a single-package module named for a DOMAIN,

9;;; not for a consumer. libevent's domain is event loops, not terminals.

10;;;

11;;; * filing it under `terminal` would encode "libevent exists to serve tmux"

12;;; in the module layout, and the next consumer of libevent will not be a

13;;; terminal program. That is the same mistake in a different place as the

14;;; builder hardcoding `include/ncursesw` for every package -- one

15;;; consumer's situation written down somewhere general.

16(define-library (core packages event)

17 (import (sigil core)

18 (core build-environments)

19 (sigil env package)

20 (sigil build external))

21 (export libevent)

22 (begin

23 ;; NO `search-paths:` DECLARATION, and that is an answered question rather

24 ;; than an omission. ncurses needs one because `--enable-widec` puts every

25 ;; header under `include/ncursesw/` and leaves `include/` empty, so the

26 ;; builder's own `-I<dep>/include` reaches nothing. libevent installs

27 ;; `event.h`, `evutil.h` and friends directly in `include/`, with the

28 ;; modern API under `include/event2/` -- and `#include <event2/event.h>`,

29 ;; which is what tmux compiles, resolves relative to `include/`. The

30 ;; builder's own flag is therefore sufficient; measured on the built store

31 ;; item, see the task note.

32 ;;

33 ;; The `.pc` files matter more than the headers here: tmux finds libevent

34 ;; through PKG_CHECK_MODULES, and the builder puts every dependency's

35 ;; `lib/pkgconfig` on PKG_CONFIG_PATH already. Measured on the installed

36 ;; item, THREE of the four generated files carry an empty `Requires:`

37 ;; (`libevent_pthreads.pc` has `Requires: libevent`) and all four carry an

38 ;; empty `Conflicts:`. That empty-dependency-list shape is what makes

39 ;; pkgconf read past the start of its buffer and abort with SIGABRT under

40 ;; Zig's runtime safety.

41 ;;

42 ;; IT IS NOT A VERSION PROBLEM AND MUST NOT BE RECORDED AS ONE. The seed's

43 ;; own build script measured the identical defective line in pkgconf 1.9.5

44 ;; (parser.c:88) and 2.4.3 (parser.c:95) and states plainly that no pkgconf

45 ;; release fixes it -- a version bump is not a fix. What makes the seed's

46 ;; pkgconf safe is a SOURCE PATCH the seed applies itself, plus two

47 ;; refusals guarding it; see seed/scripts/build-seed.sh. Naming "2.4.3" as

48 ;; the reason would invite exactly the wrong repair later.

49 ;;

50 ;; Verified against the seed's own binary on all four files this package

51 ;; installs: `--exists`, `--cflags --libs` and `--static` all exit 0, with

52 ;; an absent-package negative control still exiting 1.

53 (define libevent

54 (package

55 name: "libevent"

56 version: "2.1.13-stable"

57 source: (external-source

58

                  location: "https://github.com/libevent/libevent/releases/download/release-2.1.13-stable/libevent-2.1.13-stable.tar.gz"

59 sha256: "f7e9383b8c0baa81b687e5b5eecc01beefaf1b19b64151d95ed61647fe7a315c")

60 buildenv: core-buildenv

61 phases: (list

62 (external-phase

63 kind: 'configure

64 args: (list "--prefix=${out}"

65 ;; static only, consistent with the channel

66 "--disable-shared"

67 "--enable-static"

68 ;; openssl is not in the channel

69 "--disable-openssl"

70 ;; nothing here is installed, and both build

71 ;; test programs we would only throw away

72 "--disable-samples"

73 "--disable-libevent-regress"

74 "--disable-doxygen-html"))

75 (external-phase kind: 'make)

76 (external-phase kind: 'install))))))