BF: local-debug of online studies fetched incorrect lib version name

Really we should have a method to generate the correct version name (out
of Experiment class?) so that the same code is used during compilePsyexp
and in RunnerPanel.getPsychoJS() but for now I've just fixed in the one
place

Author: peircej

psychopy/app/runner/runner.py

@@ -6,7 +6,7 @@
 # Distributed under the terms of the GNU General Public License (GPL).
 import glob
 import json
-
+import errno
 from psychopy.app.themes._themes import ThemeSwitcher
 
 from ..themes import ThemeMixin
@@ -686,6 +686,7 @@ def runOnlineDebug(self, evt, port=12002):
                                    stderr=PIPE,
                                    shell=False,
                                    universal_newlines=True,
+
                                    )
 
         time.sleep(.1)  # Wait for subprocess to start server
@@ -702,20 +703,23 @@ def getPsychoJS(self):
 
         Useful for debugging, amending scripts.
         """
-        libPath = str(self.currentFile.parent / self.outputPath / 'lib')
-        ver = '.'.join(self.app.version.split('.')[:2])
+        libPath = self.currentFile.parent / self.outputPath / 'lib'
+        ver = '.'.join(self.app.version.split('.')[:3])
         psychoJSLibs = ['core', 'data', 'util', 'visual', 'sound']
 
-        os.path.exists(libPath) or os.makedirs(libPath)
-
-        if len(sorted(Path(libPath).glob('*.js'))) >= len(psychoJSLibs):  # PsychoJS lib files exist
-            print("##### PsychoJS lib already exists in {} #####\n".format(libPath))
-            return
+        try:  # ask-for-forgiveness rather than query-then-make
+            os.makedirs(libPath)
+        except OSError as e:
+            if e.errno != errno.EEXIST:  # we only want to ignore "exists", not others like permissions
+                raise  # raises the error again
 
         for lib in psychoJSLibs:
+            finalPath = libPath / ("{}-{}.js".format(lib, ver))
+            if finalPath.exists():
+                continue
             url = "https://lib.pavlovia.org/{}-{}.js".format(lib, ver)
             req = requests.get(url)
-            with open(libPath + "/{}-{}.js".format(lib, ver), 'wb') as f:
+            with open(finalPath, 'wb') as f:
                 f.write(req.content)
 
         print("##### PsychoJS libs downloaded to {} #####\n".format(libPath))