2 files changed, 6 insertions, 5 deletions
diff --git a/setup.py b/setup.py
index e7553aacb..462913532 100644
--- a/setup.py
+++ b/setup.py
@@ -905,8 +905,8 @@ class pyside_build(_build):
                         clangBinDir, clangDir[1]))
                     additionalPaths.append(clangBinDir)
             else:
-                log.error("Failed to detect Clang by checking "
-                    "LLVM_INSTALL_DIR, CLANG_INSTALL_DIR, llvm-config")
+                raise DistutilsSetupError("Failed to detect Clang when checking "
+                                          "LLVM_INSTALL_DIR, CLANG_INSTALL_DIR, llvm-config")
 
         update_env_path(additionalPaths)
 
diff --git a/utils.py b/utils.py
index c80e6dd6c..11d9fbc64 100644
--- a/utils.py
+++ b/utils.py
@@ -775,9 +775,10 @@ def detectClang():
         if not clangDir:
             source = findLlvmConfig()
             try:
-                output = run_process_output([source, '--prefix'])
-                if output:
-                    clangDir = output[0]
+                if source is not None:
+                    output = run_process_output([source, '--prefix'])
+                    if output:
+                        clangDir = output[0]
             except OSError:
                 pass
     if clangDir: