Fix py38 build issue (#174)

* Fix broken PyBDSF shell

As a result of the recent change where the `pybdsf` script was converted into a module with a `main` function that was defined as `entry_point` in `setup.py`, the interactive shell no longer worked properly. You could start it, but you could not execute any of the commands. This commit fixes this. It has been tested manually on FITS-file available in the test directory, and it seems to work fine.

bdsf/pybdsf.py

@@ -203,14 +203,14 @@ def _set_pars_from_prompt():
     """Gets parameters and value and stores them in _img.
 
     To do this, we extract all the valid parameter names
-    and values from the f_locals directory. Then, use
+    and values from the f_globals directory. Then, use
     set_pars() to set them all.
 
     Returns True if successful, False if not.
     """
     global _img
-    f = sys._getframe(len(inspect.stack())-1)
-    f_dict = f.f_locals
+    f = sys._getframe(len(inspect.stack())-2)
+    f_dict = f.f_globals
 
     # Check through all possible options and
     # build options dictionary
@@ -249,8 +249,8 @@ def _replace_vals_in_namespace(opt_names=None):
     opt_names - list of option names to replace (can be string if only one)
     """
     global _img
-    f = sys._getframe(len(inspect.stack())-1)
-    f_dict = f.f_locals
+    f = sys._getframe(len(inspect.stack())-2)
+    f_dict = f.f_globals
     if opt_names is None:
         opt_names = _img.opts.get_names()
     if isinstance(opt_names, str):
@@ -736,13 +736,15 @@ def out_prompt_tokens(self):
                 prompt_config.in_template = "BDSF [\#]: "
 
         cfg.InteractiveShellEmbed.autocall = 2
+        user_ns = globals()
+        user_ns.update(locals())
         ipshell = InteractiveShellEmbed(config=cfg, banner1=banner,
-                                        user_ns=locals())
+                                        user_ns=user_ns)
         ipshell.set_hook('complete_command', _opts_completer, re_key = '.*')
     except ImportError:
         # IPython < 0.11
         from IPython.Shell import IPShellEmbed
         argv = ['-prompt_in1','BDSF [\#]: ','-autocall','2']
-        ipshell = IPShellEmbed(argv=argv, banner=banner, user_ns=locals())
+        ipshell = IPShellEmbed(argv=argv, banner=banner, user_ns=user_ns)
         ipshell.IP.set_hook('complete_command', _opts_completer, re_key = '.*')
     ipshell()