diff --git a/platformio/builder/main.py b/platformio/builder/main.py
index e25d4af3..a6d71fb6 100644
--- a/platformio/builder/main.py
+++ b/platformio/builder/main.py
@@ -89,12 +89,6 @@ if not int(ARGUMENTS.get("PIOVERBOSE", 0)):
 
 env = DefaultEnvironment(**DEFAULT_ENV_OPTIONS)
 
-if env.GetOption('clean'):
-    env.PioClean(env.subst("$BUILD_DIR"))
-    env.Exit(0)
-elif not int(ARGUMENTS.get("PIOVERBOSE", 0)):
-    print("Verbose mode can be enabled via `-v, --verbose` option")
-
 # Load variables from CLI
 for key in list(clivars.keys()):
     if key in env:
@@ -102,6 +96,12 @@ for key in list(clivars.keys()):
         if isinstance(env[key], bytes):
             env[key] = env[key].decode()
 
+if env.GetOption('clean'):
+    env.PioClean(env.subst("$BUILD_DIR"))
+    env.Exit(0)
+elif not int(ARGUMENTS.get("PIOVERBOSE", 0)):
+    print("Verbose mode can be enabled via `-v, --verbose` option")
+
 env.GetProjectConfig().validate([env['PIOENV']], silent=True)
 env.LoadProjectOptions()
 env.LoadPioPlatform()
diff --git a/platformio/commands/debug/process.py b/platformio/commands/debug/process.py
index 68d76d00..a9064492 100644
--- a/platformio/commands/debug/process.py
+++ b/platformio/commands/debug/process.py
@@ -12,13 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os
-
 import click
 from twisted.internet import protocol  # pylint: disable=import-error
 
 from platformio.commands.debug import helpers
 from platformio.compat import string_types
+from platformio.proc import get_pythonexe_path
 from platformio.project.helpers import get_project_core_dir
 
 LOG_FILE = None
@@ -31,7 +30,7 @@ class BaseProcess(protocol.ProcessProtocol, object):
     COMMON_PATTERNS = {
         "PLATFORMIO_HOME_DIR": helpers.escape_path(get_project_core_dir()),
         "PLATFORMIO_CORE_DIR": helpers.escape_path(get_project_core_dir()),
-        "PYTHONEXE": os.getenv("PYTHONEXEPATH", "")
+        "PYTHONEXE": get_pythonexe_path()
     }
 
     def apply_patterns(self, source, patterns=None):