Basic example creates zombie on Mac OS

[Geod24]

Using Mac OS 11.5.2, but I believe this triggers on OSX too.

% mkdir test && cd test
% dub init -t vibe.d -n .
Successfully created an empty project in '/Users/geod24/projects/bpfk/agora/test'.
Package successfully created in .
% dub
Running pre-generate commands for vibe-d:tls...
Performing "debug" build using dmd for x86_64.
taggedalgebraic 0.11.22: target for configuration "library" is up to date.
eventcore 0.9.17: target for configuration "cfrunloop" is up to date.
stdx-allocator 2.77.5: target for configuration "library" is up to date.
vibe-core 1.19.0: target for configuration "cfrunloop" is up to date.
vibe-d:utils 0.9.3: target for configuration "library" is up to date.
vibe-d:data 0.9.3: target for configuration "library" is up to date.
mir-linux-kernel 1.0.1: target for configuration "library" is up to date.
vibe-d:crypto 0.9.3: target for configuration "library" is up to date.
diet-ng 1.8.0: target for configuration "library" is up to date.
vibe-d:stream 0.9.3: target for configuration "library" is up to date.
vibe-d:textfilter 0.9.3: target for configuration "library" is up to date.
vibe-d:inet 0.9.3: target for configuration "library" is up to date.
vibe-d:tls 0.9.3: target for configuration "openssl" is up to date.
vibe-d:http 0.9.3: target for configuration "library" is up to date.
vibe-d:mail 0.9.3: target for configuration "library" is up to date.
vibe-d:mongodb 0.9.3: target for configuration "library" is up to date.
vibe-d:redis 0.9.3: target for configuration "library" is up to date.
vibe-d:web 0.9.3: target for configuration "library" is up to date.
vibe-d 0.9.3: target for configuration "vibe-core" is up to date.
test ~master: building configuration "application"...
Linking...
To force a rebuild of up-to-date targets, run again with --force.
Running test
[main(----) INF] Listening for requests on http://[::1]:8080/
[main(----) INF] Listening for requests on http://127.0.0.1:8080/
[main(----) INF] Please open http://127.0.0.1:8080/ in your browser.
^C[main(----) INF] Received signal 2. Shutting down.

% ps aux | grep test
geod24           15024   0.0  0.0  4268448    744 s006  S+   12:04PM   0:00.00 grep --color=auto test
geod24           14999   0.0  0.1  4444224   9812 s006  S    12:03PM   0:00.02 /Users/geod24/projects/bpfk/agora/test/test
% lldb -p 14999
(lldb) process attach --pid 14999
Process 14999 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGSTOP
    frame #0: 0x00007fff203572ba libsystem_kernel.dylib`mach_msg_trap + 10
libsystem_kernel.dylib`mach_msg_trap:
->  0x7fff203572ba <+10>: retq
    0x7fff203572bb <+11>: nop

libsystem_kernel.dylib`mach_msg_overwrite_trap:
    0x7fff203572bc <+0>:  movq   %rcx, %r10
    0x7fff203572bf <+3>:  movl   $0x1000020, %eax          ; imm = 0x1000020
Target 0: (test) stopped.

Executable module set to "/Users/geod24/projects/bpfk/agora/test/test".
Architecture set to: x86_64h-apple-macosx-.
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGSTOP
  * frame #0: 0x00007fff203572ba libsystem_kernel.dylib`mach_msg_trap + 10
    frame #1: 0x00007fff2035762c libsystem_kernel.dylib`mach_msg + 60
    frame #2: 0x00007fff20485b2f CoreFoundation`__CFRunLoopServiceMachPort + 316
    frame #3: 0x00007fff2048420f CoreFoundation`__CFRunLoopRun + 1328
    frame #4: 0x00007fff2048361c CoreFoundation`CFRunLoopRunSpecific + 563
    frame #5: 0x000000010c67580a test`_D9eventcore7drivers5posix9cfrunloop18CFRunLoopEventLoop15doProcessEventsMFNbNeS4core4time8DurationZb + 202
    frame #6: 0x000000010c6777f1 test`_D9eventcore7drivers5posix6driver__T20PosixEventDriverCoreHTCQChQCaQBv9cfrunloop18CFRunLoopEventLoopHTCQDxQDq5timer22LoopTimeoutTimerDriverHTCQFkQFdQEy6events__T22PosixEventDriverEventsHTQExHTCQHjQHcQGx7sockets__T23PosixEventDriverSocketsHTQGyZQBfZQDjHTCQJsQJlQJg9processes__T25PosixEventDriverProcessesHTQJlZQBhZQKr13processEventsMFNbNfS4core4time8DurationZEQNtQMy10ExitReason + 253
    frame #7: 0x000000010c660d6b test`_D4vibe4core4task13TaskScheduler14waitAndProcessMFNbNfZE9eventcore6driver10ExitReason + 159
    frame #8: 0x000000010c63389e test`_D4vibe4coreQf12runEventLoopFNbNfZi + 294
    frame #9: 0x000000010c6336c6 test`_D4vibe4coreQf14runApplicationFNfPAAyaZi + 286
    frame #10: 0x000000010c3b6ba0 test`_Dmain at app.d:15
    frame #11: 0x000000010c72737b test`_D2rt6dmain212_d_run_main2UAAamPUQgZiZ6runAllMFZ9__lambda2MFZv + 31
    frame #12: 0x000000010c72721d test`_D2rt6dmain212_d_run_main2UAAamPUQgZiZ7tryExecMFMDFZvZv + 33
    frame #13: 0x000000010c7272f7 test`_D2rt6dmain212_d_run_main2UAAamPUQgZiZ6runAllMFZv + 139
    frame #14: 0x000000010c72721d test`_D2rt6dmain212_d_run_main2UAAamPUQgZiZ7tryExecMFMDFZvZv + 33
    frame #15: 0x000000010c72717a test`_d_run_main2 + 654
    frame #16: 0x000000010c726ed6 test`_d_run_main + 202
    frame #17: 0x000000010c3b6bfe test`main(argc=1, argv=0x00007ffee384b768) at entrypoint.d:29
    frame #18: 0x00007fff203a7f3d libdyld.dylib`start + 1
    frame #19: 0x00007fff203a7f3d libdyld.dylib`start + 1

As you can see, the most simple app creates a zombie. This is not visible to the user thanks to SO_REUSEPORT, but became a major annoyance when I created an UDP server which didn't have the option on by default.
Using Ctrl+\ is a workaround, but it bypasses the normal shutdown of the app.

Using dub / ldc packaged with Homebrew:

% ldc2 --version
LDC - the LLVM D compiler (1.27.1):
  based on DMD v2.097.2 and LLVM 12.0.1
  built with LDC - the LLVM D compiler (1.27.1)
  Default target: x86_64-apple-darwin20.6.0
  Host CPU: skylake
  http://dlang.org - http://wiki.dlang.org/LDC
% dub --version
DUB version 1.26.1, built on Jul 20 2021