Update guide_seafile.rst

[fredl99]

Added version to pip3 install Pillow because seahub.sh will not start when a newer package is installed.
Beware of blindly initiated updates! This way I was caught by this problem. Took me two days to figure it out.

[noave]

thanks, do you have any insights if this problem will be fixed in seahub? Because if we lock a specific pillow version here, this might cause problems in the future

[fredl99]

Not at all, I'm sorry. I'm neither a python pro nor do I have any insight on seafile.
I was already glad I could fix that issue by replacing some modules from a backup. That was the last idea I could try.

[korakinos]

From my own experiments, this has less to do with the version of Pillow than with the version of Python. With python3.8 and pip3.8, specifying the version of Pillow is not necessary.

To be a bit more precise, when calling seahub as seahub.sh start-fastcgi one gets an error message involving Pillow and "PyIndex_Check":

"ImportError: /home/korakin1/.local/lib/python3.6/site-packages/PIL/_imaging.cpython-36m-x86_64-linux-gnu.so: undefined symbol: PyIndex_Check"

Turns out, PyIndex_Check was only defined as a function in Python 3.8, which makes its use in Pillow fail with 3.6:

python/cpython#77919
python/cpython@5cbefa9

In fact, I was just meaning to create a pull request from my fork of the guide when I found this one:

https://github.com/korakinos/lab/tree/update-seafile

[korakinos]

Here is the pull request from my fork:

#1260

[fredl99]

Thanks for the explanation @korakinos

As I stated, I'm no python expert at all. I've followed the lab's tutorial and got a beautifully running seafile-server until some modules were updated. Without any clue my best idea was to revert them. That's how I came to my conclusion.

BTW: After your explanation I just checked the default python3 version at uberspace7: Python 3.6.8
As I understand your message, the better solution would be to run all commands with a newer version than the default.

BTW2: I don't use start-fastcgi. With start the error message is much shorter. Something like "didn't start". Not much help.

[korakinos]

As I stated, I'm no python expert at all.

Me neither! I also just tried to follow the tutorial and figured out a way to make it work.

BTW: After your explanation I just checked the default python3 version at uberspace7: Python 3.6.8 As I understand your message, the better solution would be to run all commands with a newer version than the default.

Yes. 3.6 is not supported anymore.

https://peps.python.org/pep-0494/
https://en.wikipedia.org/wiki/History_of_Python#Table_of_versions

BTW2: I don't use start-fastcgi. With start the error message is much shorter. Something like "didn't start". Not much help.

Yeah, it's really not obvious that start-fastcgi has better error messages! If I hadn't found this trick on some forum (forgot where), I would have been pretty lost…

[noave]

because the guide has been removed anyway, I will close this as well a2e3205