vulkan: Test Vulkan version in SDK path

This change ensures that Vulkan will be found in the path defined by the
VULKAN_SDK env var. This is the case when the Vulkan SDK is not
installed in a well-known location (/usr, /usr/local), but in a user's
home folder.

Author: amolenaar

mesonbuild/dependencies/ui.py

@@ -191,6 +191,7 @@ def __init__(self, name: str, environment: 'Environment', kwargs: T.Dict[str, T.
         if self.vulkan_sdk and not os.path.isabs(self.vulkan_sdk):
             raise DependencyException('VULKAN_SDK must be an absolute path.')
 
+        extra_args = []
         if self.vulkan_sdk:
             # TODO: this config might not work on some platforms, fix bugs as reported
             # we should at least detect other 64-bit platforms (e.g. armv8)
@@ -219,6 +220,7 @@ def __init__(self, name: str, environment: 'Environment', kwargs: T.Dict[str, T.
             # XXX: this is very odd, and may deserve being removed
             self.type_name = DependencyTypeName('vulkan_sdk')
             self.is_found = True
+            extra_args = ['-I' + inc_path]
             self.compile_args.append('-I' + inc_path)
             self.link_args.append('-L' + lib_path)
             self.link_args.append('-l' + lib_name)
@@ -239,7 +241,7 @@ def __init__(self, name: str, environment: 'Environment', kwargs: T.Dict[str, T.
                                                                  low=0, high=None, guess=e,
                                                                  prefix='#include <vulkan/vulkan.h>',
                                                                  env=environment,
-                                                                 extra_args=None,
+                                                                 extra_args=extra_args,
                                                                  dependencies=None))
                               # list containing vulkan version components and their expected value
                               for c, e in [('MAJOR', 1), ('MINOR', 3), ('PATCH', None)]]