Index: buildbot/osuosl/master/config/builders.py
===================================================================
--- buildbot/osuosl/master/config/builders.py
+++ buildbot/osuosl/master/config/builders.py
@@ -467,6 +467,7 @@
                     clean=False,
                     checkout_flang=True,
                     checkout_lld=False,
+                    enable_runtimes="auto",
                     useTwoStage=True,
                     testStage1=False,
                     runTestSuite=True,
Index: zorg/buildbot/builders/ClangBuilder.py
===================================================================
--- zorg/buildbot/builders/ClangBuilder.py
+++ zorg/buildbot/builders/ClangBuilder.py
@@ -166,7 +166,9 @@
             checkout_lld=True,
             checkout_libcxx=False,
             checkout_flang=False,
-            checkout_test_suite=False):
+            checkout_test_suite=False,
+
+            enable_runtimes=None):
     return _getClangCMakeBuildFactory(
                clean=clean, checks=checks, cmake=cmake, jobs=jobs, vs=vs,
                vs_target_arch=vs_target_arch, useTwoStage=useTwoStage,
@@ -180,7 +182,8 @@
                checkout_compiler_rt=checkout_compiler_rt,
                checkout_libcxx=checkout_libcxx,
                checkout_flang=checkout_flang,
-               checkout_test_suite=checkout_test_suite)
+               checkout_test_suite=checkout_test_suite,
+               enable_runtimes=enable_runtimes)
 
 def _getClangCMakeBuildFactory(
             clean=True,
@@ -218,6 +221,8 @@
             checkout_test_suite=False,
             checkout_flang=False,
 
+            enable_runtimes=None,
+
             # Upload artifacts to Google Cloud Storage (for the llvmbisect tool)
             stage1_upload_directory=None,
 
@@ -267,7 +272,8 @@
 
     f = LLVMBuildFactory(
             depends_on_projects=depends_on_projects,
-            llvm_srcdir='llvm')
+            llvm_srcdir='llvm',
+            enable_runtimes=enable_runtimes)
 
     # Checkout the latest code for LNT
     # and the test-suite separately. Le's do this first,