2020-09-11 17:55 UTC, Markus Wageringel: > > With a clean build on Ubuntu 20.04, ptestlong passes, but Jupyter > does not start anymore due to an SSL problem, using Sage's Python 3. > (The system Python 3.8 is not picked up because of missing > dependencies sqlite and xz, but that is ok.) > > $ ./sage -n jupyter > Please wait while the Sage Jupyter Notebook server starts... > Traceback (most recent call last): > ... > import _ssl # if we can't import it, let the error > propagate > ModuleNotFoundError: No module named '_ssl' > > The Jupyter notebook requires ssl, even if you do not use > https. Install the openssl development packages in your system and > then rebuild Python (sage -f python3). > > Which packages need to be installed for this and why was this not > a problem previously? OpenSSL is installed on the system: > > $ openssl version > OpenSSL 1.1.1f 31 Mar 2020
The build system apparently did not build Python's `_ssl` module when it built Python. It is supposed to always build it provided openssl is present, either from the system or built as an spkg. Or could it be that your system has OpenSSL but not libssl-dev, as Matthias suggests? 2020-09-11 18:17 UTC, Matthias Köppe: > > Is "libssl-dev" installed? > (see build/pkgs/openssl/distros/debian.txt) On Debian or Debian-based system like Ubuntu, check whether libssl-dev is installed with this command (sudo not needed): ``` $ dpkg-query --list libssl-dev ``` If indeed it was not installed, do this: ``` $ sudo apt install libssl-dev $ ./sage -f python3 ``` Oh, but you replied to Matthias now: 2020-09-11 18:34 UTC, Markus Wageringel > > It looks like it is not: In the meantime I had opened a ticket: - Build Python's ssl module https://trac.sagemath.org/ticket/30556 in which I forgot about the libssl vs libssl-dev subtlety. I'll change the ticket's goal to - Warn when building Python without its SSL module I know when there are errors, they are summarized at the end of the build. Do we have a mechanism to collect warnings and summarise them at the end of the build? It would be very useful when building on a system without the appropriate ssl dependencies like yours or most macOS systems to end the build with a word such as Sage was successfully built, and starts, but be warned, it build its own Python without the SSL module. To know more, visit <some documentation or wiki page> Would there be a way to make `sage -n jupyter` first check for the ssl module, and if it is not found provide some helpful error message with hints as to how to fix things? If you get a chance to ask someone with sudo rights on the machine you were using, have them install all the pieces you were missing: xz, sqlite, libssl-dev, for next time! See at the end of the output of `./configure` for a list of recommended packages to install system-wide. In the meantime a workaround as you guessed is to build Sage's openssl spkg and rebuild Sage's Python so it takes advantage of it: ``` $ ./sage -i openssl $ ./sage -f python3 ``` This last command will also rebuild any packages that depend on the `python3` spkg. -- You received this message because you are subscribed to the Google Groups "sage-release" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-release+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-release/CAEcArF1hjuRS0u982FznHqjQcN6aopJHmAbmHbs44yHrTbgcpw%40mail.gmail.com.
