As @merve mentioned, setting debug=True is a good idea. On top of that, once you see the fail message, you can click in “Running” or “Build error” next to the like count, and that will actually show you the logs.  FYI we have an internal PR to make this a clear button.
Eg, for your space, I see the following error

During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File “/home/user/.local/lib/python3.8/site-packages/nltk/corpus/util.py”, line 84, in __load
root = nltk.data.find(f"{self.subdir}/{zip_name}")
File “/home/user/.local/lib/python3.8/site-packages/nltk/data.py”, line 583, in find
raise LookupError(resource_not_found)
LookupError:

Resource e[93mstopwordse[0m not found.
Please use the NLTK Downloader to obtain the resource:
e[31m>>> import nltk



nltk.download(‘stopwords’)
e[0m
For more information see: NLTK :: Installing NLTK Data



Attempted to load e[93mcorpora/stopwords.zip/stopwords/e[0m
Searched in:
- ‘/home/user/nltk_data’
- ‘/usr/local/nltk_data’
- ‘/usr/local/share/nltk_data’
- ‘/usr/local/lib/nltk_data’
- ‘/usr/share/nltk_data’
- ‘/usr/local/share/nltk_data’
- ‘/usr/lib/nltk_data’
- ‘/usr/local/lib/nltk_data’

During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File “/home/user/.local/lib/python3.8/site-packages/gradio/networking.py”, line 196, in predict
prediction, durations = app.interface.process(raw_input)
File “/home/user/.local/lib/python3.8/site-packages/gradio/interface.py”, line 373, in process
predictions, durations = self.run_prediction(
File “/home/user/.local/lib/python3.8/site-packages/gradio/interface.py”, line 339, in run_prediction
prediction = predict_fn(*processed_input)
File “app.py”, line 86, in chat
response = ask_gpt(message)
File “app.py”, line 57, in ask_gpt
prompt = clean(message)  # clean user input
File “/home/user/.local/lib/python3.8/site-packages/cleantext/cleantext.py”, line 8, in clean
stop_words = nltk.corpus.stopwords.words(stp_lang)
File “/home/user/.local/lib/python3.8/site-packages/nltk/corpus/util.py”, line 121, in getattr
self.__load()
File “/home/user/.local/lib/python3.8/site-packages/nltk/corpus/util.py”, line 86, in __load
raise e
File “/home/user/.local/lib/python3.8/site-packages/nltk/corpus/util.py”, line 81, in __load
root = nltk.data.find(f"{self.subdir}/{self.__name}")
File “/home/user/.local/lib/python3.8/site-packages/nltk/data.py”, line 583, in find
raise LookupError(resource_not_found)
LookupError:

Resource e[93mstopwordse[0m not found.
Please use the NLTK Downloader to obtain the resource:
e[31m>>> import nltk



nltk.download(‘stopwords’)
e[0m
For more information see: NLTK :: Installing NLTK Data



Attempted to load e[93mcorpora/stopwordse[0m
Searched in:
- ‘/home/user/nltk_data’
- ‘/usr/local/nltk_data’
- ‘/usr/local/share/nltk_data’
- ‘/usr/local/lib/nltk_data’
- ‘/usr/share/nltk_data’
- ‘/usr/local/share/nltk_data’
- ‘/usr/lib/nltk_data’
- ‘/usr/local/lib/nltk_data’