Streamlit should fail gracefully if `server.port` is already in use. about streamlit HOT 4 CLOSED

While this bug is not fixed, a quick (very imperfect) fix is to kill all processes containing the work streamlit by running pkill -f streamlit as follows:

$ streamlit run my_app.py # <- trying to run for the first time
Traceback (most recent call last):
...
OSError: [Errno 48] Address already in use
$ pkill -f streamlit
$ streamlit run my_app.py # <- this time it should work

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When running multiple instances of the same thing I usually don't care which port it is running at, shouldn't it default to the next available port? Nothing in the website part or the server part makes me think knowing the port -or deciding which port it is going to be- relevant

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@dnuske : Yes. That would be even better.

from streamlit.

after careful analysis it was decided that if the port is not set up explicitly in the config then it will rotate (add 1 to the current default one and try to run the server), but if it was set up by the user a pretty error would appear.

If it is desired we can ask the user by prompt to pick a new port, but that would be over featured considering that the ability to pass the --server.port option will soon be available

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