diff --git a/src/gn/exec_process.cc b/src/gn/exec_process.cc
index eeebcb4..2f001bf 100644
--- a/src/gn/exec_process.cc
+++ b/src/gn/exec_process.cc
@@ -204,6 +204,13 @@
       return false;
     case 0:  // child
     {
+#if defined(OS_MAC)
+      // When debugging the app under Xcode, the child will receive a SIGTRAP
+      // signal which will terminate the child process. Ignore the signal to
+      // allow debugging under macOS.
+      sigignore(SIGTRAP);
+#endif
+
       // DANGER: no calls to malloc are allowed from now on:
       // http://crbug.com/36678
       //