MacOS Monterey deprecated vfork system call

[tmcgilchrist]

When compiling this package on Monterey 12.4:

spawn_stubs.c:491:33: warning: 'vfork' is deprecated: Use posix_spawn or fork [-Wdeprecated-declarations]
  ret = Bool_val(v_use_vfork) ? vfork() : fork();
                                ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/unistd.h:604:1: note: 'vfork' has been explicitly marked deprecated here
__deprecated_msg("Use posix_spawn or fork")
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/sys/cdefs.h:208:48: note: expanded from macro '__deprecated_msg'
        #define __deprecated_msg(_msg) __attribute__((__deprecated__(_msg)))
                                                      ^
1 warning generated.

then running the tests fails with an unrelated error, /usr/bin/sleep doesn't exist on Monterey.

$ dune build @runtest
File "test/tests.ml", line 147, characters 0-480: sigprocmask threw Unix.Unix_error(Unix.ENOENT, "execve", "/usr/bin/sleep").
  Raised by primitive operation at Spawn.spawn in file "src/spawn.ml" (inlined), line 162, characters 6-16
  Called from Spawn.spawn in file "src/spawn.ml", line 169, characters 2-87
  Called from Spawn_test__Tests.(fun).run in file "test/tests.ml", line 150, characters 16-81
  Called from Spawn_test__Tests.(fun) in file "test/tests.ml", line 157, characters 4-19

FAILED 1 / 9 tests

This package should update to use fork(2) or, ideally, posix_spawn(3) as suggested in man vfork 2.

[tov]

Here’s a PR for this issue: #39.

[tov]

Having looked into posix_spawn, I think it doesn't quite let us implement our API, because it doesn't provide any mechanism for returning an error from the execve(2) call, nor for distinguishing other post-fork errors.

[aalekseyev]

Another reason we don't use posix_spawn is that it doesn't let you change the current working directory, as far as I know.

[tov]

Standard posix_spawn doesn’t let you chdir, but macOS posix_spawn does.

…

On Jul 26, 2022, at 11:04, Arseniy Alekseyev ***@***.***> wrote:  Another reason we don't use posix_spawn is that it doesn't let you change the current working directory, as far as I know. — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you commented.