Feat: Make exception raised by external command authenticator more ac…

…tionable (flyteorg#2594)

Signed-off-by: Fabio Grätz <fabiogratz@googlemail.com>
Co-authored-by: Fabio Grätz <fabiogratz@googlemail.com>

flytekit/clients/auth/authenticator.py

@@ -179,12 +179,15 @@ def refresh_credentials(self):
         This function is used when the configuration value for AUTH_MODE is set to 'external_process'.
         It reads an id token generated by an external process started by running the 'command'.
         """
-        logging.debug("Starting external process to generate id token. Command {}".format(self._cmd))
+        cmd_joined = " ".join(self._cmd)
+        logging.debug("Starting external process to generate id token. Command `{}`".format(" ".join(cmd_joined)))
         try:
             output = subprocess.run(self._cmd, capture_output=True, text=True, check=True)
-        except subprocess.CalledProcessError as e:
-            logging.error("Failed to generate token from command {}".format(self._cmd))
-            raise AuthenticationError("Problems refreshing token with command: " + str(e))
+        except subprocess.CalledProcessError:
+            logging.error("Failed to generate token from command `{}`".format(cmd_joined))
+            raise AuthenticationError(
+                f"Failed to refresh token with command `{cmd_joined}`. Please execute this command in your terminal to debug."
+            )
         self._creds = Credentials(output.stdout.strip())