Switch lldb-x86_64-debian to python3
diff --git a/buildbot/osuosl/master/config/builders.py b/buildbot/osuosl/master/config/builders.py
index 2db92a3..c2a17d6 100644
--- a/buildbot/osuosl/master/config/builders.py
+++ b/buildbot/osuosl/master/config/builders.py
@@ -892,6 +892,7 @@
                     extra_cmake_args=['-DLLVM_ENABLE_ASSERTIONS=True',
                                       '-DLLVM_USE_LINKER=gold',
                                       '-DLLDB_ENABLE_PYTHON=True',
+                                      '-DPYTHON_EXECUTABLE=/usr/bin/python3',
                                       '-DCMAKE_C_COMPILER=clang',
                                       '-DCMAKE_CXX_COMPILER=clang++'])},
         {'name': "lldb-aarch64-ubuntu",