support multiple --config-settings

_custom_build/backend.py

@@ -12,13 +12,11 @@ class _CustomBuildMetaBackend(backend_class):
     def run_setup(self, setup_script="setup.py"):
         if self.config_settings:
             params = []
-            for k, v in self.config_settings.items():
-                if isinstance(v, list):
-                    msg = "Conflicting options: " + ", ".join(
-                        f"'--config-setting {k}={v_}'" for v_ in v
-                    )
-                    raise ValueError(msg)
-                params.append(f"--pillow-configuration={k}={v}")
+            for key, values in self.config_settings.items():
+                if not isinstance(values, list):
+                    values = [values]
+                for value in values:
+                    params.append(f"--pillow-configuration={key}={value}")
 
             sys.argv = sys.argv[:1] + params + sys.argv[1:]
         return super().run_setup(setup_script)

setup.py

@@ -339,7 +339,7 @@ def __iter__(self):
 
     @staticmethod
     def check_configuration(option, value):
-        return True if configuration.get(option) == value else None
+        return True if value in configuration.get(option, []) else None
 
     def initialize_options(self):
         self.disable_platform_guessing = self.check_configuration(
@@ -354,7 +354,7 @@ def initialize_options(self):
             setattr(self, f"vendor_{x}", self.check_configuration(x, "vendor"))
         if self.check_configuration("debug", "true"):
             self.debug = True
-        self.parallel = configuration.get("parallel")
+        self.parallel = configuration.get("parallel", [None])[-1]
 
     def finalize_options(self):
         build_ext.finalize_options(self)
@@ -402,9 +402,6 @@ def finalize_options(self):
                     raise ValueError(msg)
                 _dbg("Using vendored version of %s", x)
                 self.feature.vendor.add(x)
-                if x == "raqm":
-                    _dbg("--vendor-raqm implies --enable-raqm")
-                    self.feature.required.add(x)
 
     def _update_extension(self, name, libraries, define_macros=None, sources=None):
         for extension in self.extensions:
@@ -1004,11 +1001,7 @@ def debug_build():
 # parse configuration from _custom_build/backend.py
 while len(sys.argv[1]) >= 2 and sys.argv[1].startswith("--pillow-configuration="):
     _, key, value = sys.argv[1].split("=", 2)
-    old = configuration.get(key)
-    if old is not None:
-        msg = f"Conflicting options: '-C {key}={old}' and '-C {key}={value}'"
-        raise ValueError(msg)
-    configuration[key] = value
+    configuration.setdefault(key, []).append(value)
     del sys.argv[1]
 
 try: