defer setting values until after we know it cannot be None

mesonbuild/dependencies/cmake.py

@@ -126,9 +126,10 @@ class CMakeDependency(ExternalDependency):
         cm_args = check_cmake_args(cm_args)
         if CMakeDependency.class_cmakeinfo[self.for_machine] is None:
             CMakeDependency.class_cmakeinfo[self.for_machine] = self._get_cmake_info(cm_args)
-        self.cmakeinfo = CMakeDependency.class_cmakeinfo[self.for_machine]
-        if self.cmakeinfo is None:
+        cmakeinfo = CMakeDependency.class_cmakeinfo[self.for_machine]
+        if cmakeinfo is None:
             raise self._gen_exception('Unable to obtain CMake system information')
+        self.cmakeinfo = cmakeinfo
 
         package_version = kwargs.get('cmake_package_version', '')
         if not isinstance(package_version, str):

mesonbuild/dependencies/pkgconfig.py

@@ -277,13 +277,14 @@ class PkgConfigDependency(ExternalDependency):
         super().__init__(DependencyTypeName('pkgconfig'), environment, kwargs, language=language)
         self.name = name
         self.is_libtool = False
-        self.pkgconfig = PkgConfigInterface.instance(self.env, self.for_machine, self.silent)
-        if not self.pkgconfig:
+        pkgconfig = PkgConfigInterface.instance(self.env, self.for_machine, self.silent)
+        if not pkgconfig:
             msg = f'Pkg-config for machine {self.for_machine} not found. Giving up.'
             if self.required:
                 raise DependencyException(msg)
             mlog.debug(msg)
             return
+        self.pkgconfig = pkgconfig
 
         version = self.pkgconfig.version(name)
         if version is None:

mesonbuild/wrap/wrap.py

@@ -404,12 +404,13 @@ class Resolver:
     def resolve(self, packagename: str, force_method: T.Optional[Method] = None) -> T.Tuple[str, Method]:
         self.packagename = packagename
         self.directory = packagename
-        self.wrap = self.wraps.get(packagename)
-        if not self.wrap:
-            self.wrap = self.get_from_wrapdb(packagename)
-        if not self.wrap:
+        wrap = self.wraps.get(packagename)
+        if not wrap:
+            wrap = self.get_from_wrapdb(packagename)
+        if not wrap:
             m = f'Neither a subproject directory nor a {self.packagename}.wrap file was found.'
             raise WrapNotFoundException(m)
+        self.wrap = wrap
         self.directory = self.wrap.directory
 
         if self.wrap.has_wrap: