Check for existing libclingJupyter, not whether it's executable.

tools/Jupyter/kernel/clingkernel.py

@@ -62,7 +62,7 @@ class ClingKernel(Kernel):
                      'codemirror_mode': 'text/x-c++src',
                      'mimetype': ' text/x-c++src',
                      'file_extension': '.c++'}
-    
+
     flush_interval = Float(0.25, config=True)
 
     def __init__(self, **kwargs):
@@ -80,12 +80,12 @@ class ClingKernel(Kernel):
 
         for ext in ['so', 'dylib', 'dll']:
             libFilename = clingInstDir + "/lib/libclingJupyter." + ext
-            if os.access(libFilename, os.X_OK):
+            if os.access(libFilename, os.R_OK):
                 self.libclingJupyter = ctypes.CDLL(clingInstDir + "/lib/libclingJupyter." + ext,
                                                    mode = ctypes.RTLD_GLOBAL)
                 break
 
-        if not self.libclingJupyter:
+        if not getattr(self, 'libclingJupyter', None):
             raise RuntimeError('Cannot find ' + clingInstDir + '/lib/libclingJupyter.{so,dylib,dll}')
 
         self.libclingJupyter.cling_create.restype = my_void_p
@@ -101,10 +101,10 @@ class ClingKernel(Kernel):
         self.output_thread = threading.Thread(target=self.publish_pipe_output)
         self.output_thread.daemon = True
         self.output_thread.start()
-    
+
     def _recv_dict(self, pipe):
         """Receive a serialized dict on a pipe
-        
+
         Returns the dictionary.
         """
         # Wire format:
@@ -135,13 +135,13 @@ class ClingKernel(Kernel):
             value = os.read(pipe, len_value).decode('utf8')
             data[key] = value
         return data
-        
+
     def publish_pipe_output(self):
         """Watch output_pipe for display-data messages
-        
+
         and publish them on IOPub when they arrive
         """
-        
+
         while True:
             select.select([self.output_pipe], [], [])
             data = self._recv_dict(self.output_pipe)
@@ -163,13 +163,13 @@ class ClingKernel(Kernel):
             c_flush_p = c_stderr_p
         else:
             raise ValueError("Name must be stdout or stderr, not %r" % name)
-        
+
         real_fd = getattr(sys, '__%s__' % name).fileno()
         save_fd = os.dup(real_fd)
         pipe_out, pipe_in = os.pipe()
         os.dup2(pipe_in, real_fd)
         os.close(pipe_in)
-        
+
         # make pipe_out non-blocking
         flags = fcntl(pipe_out, F_GETFL)
         fcntl(pipe_out, F_SETFL, flags|os.O_NONBLOCK)
@@ -201,7 +201,7 @@ class ClingKernel(Kernel):
             libc.fflush(c_flush_p)
             os.close(real_fd)
             t.join()
-            
+
             # and restore original stdout
             os.close(pipe_out)
             os.dup2(save_fd, real_fd)
@@ -220,7 +220,7 @@ class ClingKernel(Kernel):
                 'user_expressions': {},
             }
         status = 'ok'
-        
+
         with self.forward_stream('stdout'), self.forward_stream('stderr'):
             stringResult = self.run_cell(code, silent)
 
@@ -266,7 +266,7 @@ class ClingKernel(Kernel):
             })
         else:
             raise ValueError("Invalid status: %r" % status)
-        
+
         return reply
 
     def do_complete(self, code, cursor_pos):