Xcode: this is what happens when you do not treat command lines as arrays.

mesonbuild/backend/xcodebackend.py

diff --git a/mesonbuild/backend/xcodebackend.py b/mesonbuild/backend/xcodebackend.py
index cbc478a..3ddf1cd 100644
--- a/mesonbuild/backend/xcodebackend.py
+++ b/mesonbuild/backend/xcodebackend.py
@@ -1256,6 +1256,7 @@
             if args:
                 quoted_args = []
                 for a in args:
+                    a = a.replace(r'"', r'\\\"')
                     if ' ' in a:
                         a = r'\"' + a + r'\"'
                     quoted_args.append(a)