diff --git a/debuginfo-tests/lit.cfg.py b/debuginfo-tests/lit.cfg.py
--- a/debuginfo-tests/lit.cfg.py
+++ b/debuginfo-tests/lit.cfg.py
@@ -110,15 +110,17 @@
   llvm_config.with_environment('PATHTOCLANG',
                                add_host_triple(llvm_config.config.clang))
   llvm_config.with_environment('PATHTOCLANGPP',
-                               add_host_triple(llvm_config.use_llvm_tool('clang++')))
+                               add_host_triple(llvm_config.use_llvm_tool(
+                                                  'clang++', search_env='CLANGPP')))
   llvm_config.with_environment('PATHTOCLANGCL',
-                               add_host_triple(llvm_config.use_llvm_tool('clang-cl')))
+                               add_host_triple(llvm_config.use_llvm_tool(
+                                                  'clang-cl', search_env='CLANGCL')))
 else:
   print('Host triple {} not supported. Skipping dexter tests in the '
         'debuginfo-tests project.'.format(config.host_triple))
 
 # Check which debuggers are available:
-built_lldb = llvm_config.use_llvm_tool('lldb', search_env='CLANG')
+built_lldb = llvm_config.use_llvm_tool('lldb', search_env='LLDB')
 lldb_path = None
 if built_lldb is not None:
     lldb_path = built_lldb
diff --git a/llvm/utils/lit/lit/TestingConfig.py b/llvm/utils/lit/lit/TestingConfig.py
--- a/llvm/utils/lit/lit/TestingConfig.py
+++ b/llvm/utils/lit/lit/TestingConfig.py
@@ -22,8 +22,9 @@
             }
 
         pass_vars = ['LIBRARY_PATH', 'LD_LIBRARY_PATH', 'SYSTEMROOT', 'TERM',
-                     'CLANG', 'LD_PRELOAD', 'ASAN_OPTIONS', 'UBSAN_OPTIONS',
-                     'LSAN_OPTIONS', 'ADB', 'ANDROID_SERIAL', 'SSH_AUTH_SOCK',
+                     'CLANG', 'CLANGPP', 'CLANGCL', 'LLDB', 'LD_PRELOAD',
+                     'ASAN_OPTIONS', 'UBSAN_OPTIONS', 'LSAN_OPTIONS', 'ADB',
+                     'ANDROID_SERIAL', 'SSH_AUTH_SOCK',
                      'SANITIZER_IGNORE_CVE_2016_2143', 'TMPDIR', 'TMP', 'TEMP',
                      'TEMPDIR', 'AVRLIT_BOARD', 'AVRLIT_PORT',
                      'FILECHECK_OPTS', 'VCINSTALLDIR', 'VCToolsinstallDir',