check for PDAL_DRIVER_PATH in the environment before accessing

Author: hobu

src/pdal/__init__.py

@@ -1,5 +1,5 @@
 __all__ = ["Pipeline", "Stage", "Reader", "Filter", "Writer", "dimensions", "info"]
-__version__ = '3.4.2'
+__version__ = '3.4.3'
 
 from . import libpdalpython
 from .drivers import inject_pdal_drivers

src/pdal/__main__.py

@@ -18,7 +18,8 @@ def __dir__() -> list[str]:
 
 
 def print_driver_path(args):
-    print (os.environ['PDAL_DRIVER_PATH'])
+    if 'PDAL_DRIVER_PATH' in os.environ:
+        print (os.environ['PDAL_DRIVER_PATH'])
 
 def print_plugin_path(args):
     purelib = sysconfig.get_paths()["purelib"]