grab the GIL when our plugins are intitializing the interpreter

pdal/plang/Environment.cpp

@@ -114,9 +114,20 @@ EnvironmentPtr Environment::get()
 
     auto init = []()
     {
+        PyGILState_STATE gstate;
+
+        // If the interpreter is already initialized, we need to
+        // grab the GIL and hold it before we go do any Python
+        // stuff
+        bool alreadyInitialized(Py_IsInitialized());
+        if (alreadyInitialized)
+            gstate = PyGILState_Ensure();
+
         g_environment = new Environment();
+
+        if (alreadyInitialized)
+            PyGILState_Release(gstate);
     };
-    gil_scoped_acquire acquire;
     std::call_once(flag, init);
     return g_environment;
 }

pdal/plang/gil.hpp

@@ -45,6 +45,8 @@ class gil_scoped_release {
 };
 
 
+
+
 } // plang
 
 }  // pdal