os.execShellCmd: fixes #10231 (#10232)

Darwin has long deprecated the wait union, but their macros still assume
it unless you define _POSIX_C_SOURCE. This trips up C++ compilers.

This commit duplicates the behavior of WEXITSTATUS when _POSIX_C_SOURCE
is defined.

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/pure/os.nim b/lib/pure/os.nim
index a218121ed..3a959d4e2 100644
--- a/lib/pure/os.nim
+++ b/lib/pure/os.nim
@@ -1297,7 +1297,9 @@ proc execShellCmd*(command: string): int {.rtl, extern: "nos$1",
   ## the process has finished. To execute a program without having a
   ## shell involved, use the `execProcess` proc of the `osproc`
   ## module.
-  when defined(posix):
+  when defined(macosx):
+    result = c_system(command) shr 8
+  elif defined(posix):
     result = WEXITSTATUS(c_system(command))
   else:
     result = c_system(command)