Ytukyg

When I start PyCharm for remote python interpreter, it always performs "Uploading PyCharm helpers", even when the remote machine IP is the same and already containing previously uploaded helpers. Is the behaviour correct?

This is a well known problem that can be a major obstacle in productivity especially if you use disposable instances in your workflow. It leads to a forced coffee break of 20 minutes every time you want to connect to a remote system. Unacceptable.

Seems like PyCharm creates a build.txt file in the remote helper folder that just has the current PyCharm build number as its contents, for instance:

PY-171.4694.38

So it's possible to upload the helpers manually by using rsync on /Applications/PyCharm.app/Contents/helpers/ and finally manually creating a build.txt file with your current build number. After that, PyCharm should not attempt to re-upload them.

Example:

 $ rsync -avz /Applications/PyCharm.app/Contents/helpers/ cluster:/home/xapple/.pycharm_helpers/

 $ echo "PY-171.4694.38" > /home/xapple/.pycharm_helpers/build.txt

 $ python /home/xapple/.pycharm_helpers/pydev/setup_cython.py build_ext --inplace

According to the docs,

PyCharm checks remote helpers version on every remote run, so if you update your PyCharm version, the new helpers will be uploaded automatically and you don't need to recreate remote interpreter.

fast (less than 3 second between me an digitalocean) solution inspired by excellent xApple's answer

on remote server:

export SOURCE=<your ip>

export PORT=9000

export HELPERS=$HOME/.pycharm_helpers

# PyCharm Help -> About

export BUILD=PY-172.4343.24  # 2017/10/11

cd  $HELPERS

rm -fr *

# my OS - ubuntu, change firewall rules to yours if you're not so lucky

sudo ufw allow from $SOURCE proto tcp to any port $PORT

netcat -l -v -p $PORT | tar xz # here you waiting for connection

# after finish

sudo ufw delete allow from $SOURCE proto tcp to any port $PORT

echo -n $BUILD > build.txt

python $HELPERS/pydev/setup_cython.py build_ext --inplace

on your workstation:

export TARGET=<remote server ip>

export PORT=9000

export HELPERS=<path to helpers> # for me it's $HOME/opt/pycharm-2016.3/helpers

cd $HELPERS

tar cfz - . | netcat -v $TARGET $PORT

Turning off the firewall addressed the problem in my case (macOS - Mojave). Note that this is not a general solution as it was not tested in any other environments/OS.

Note that -- at least as late as version 2018.3.x -- PyCharm also appears to require re-uploading of the helpers when the local network connection changes as well, for some reason.

What I've observed in my case is that if, while PyCharm remains running, I relocate my laptop and connect to a different LAN, the next remote debugging session I initiate will trigger the lengthy helper upload. It turns out that the contents of the helpers directory actually uploaded in this case are exactly identical to the contents already present in that directory on the remote system (I compared them), so this upload is entirely superfluous, but PyCharm isn't able to detect this.

As there's no way I know of in PyCharm to bypass or cancel automatic helpers upload, the only recourse is to completely exit from PyCharm (close all open project windows) after each change of network connection and restart the IDE. In my experience, this will cause the helper upload to succeed in the "checking remote helpers" phase, before actually uploading all the helpers again. Of course, this is major annoyance if you have multiple projects open, but it's faster than waiting the (tens of) minutes for the agonizingly slow helpers upload to complete.

All of what other responders describe for the course of action to take when changing PyCharm versions is true. It is sufficient to use rsync, ftp, scp, or whatever to transfer the contents of the new local helpers directory (on Linux, a subdirectory of where the app is installed) to the remote system (on Linux, ~/.pycharm_helpers, where ~ is the home directory of the user name used for the remote debugging session), and update the remote build.txt in the helpers directory with the new PyCharm version.