Tuesday, December 18, 2018

Today I got this one while working in PyCharm:

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x00007fa4ea4c2093, pid=4390, tid=0x00007fa4d434a700
#
# JRE version: OpenJDK Runtime Environment (8.0_152-b16) (build 1.8.0_152-release-1343-b16)
# Java VM: OpenJDK 64-Bit Server VM (25.152-b16 mixed mode linux-amd64 compressed oops)
# Problematic frame:
# V  [libjvm.so+0x4c0093]  Par_MarkFromRootsClosure::scan_oops_in_oop(HeapWord*)+0x1d3
#
# Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#
# An error report file with more information is saved as:
# /home/luc/java_error_in_PYCHARM_4390.log
#
# If you would like to submit a bug report, please visit:
#   http://bugreport.java.com/bugreport/crash.jsp
#
Aborted (core dumped)

The log file says among others:

Memory: 4k page, physical 8107960k(890004k free), swap 8324092k(8322300k free)

After reading this, I deactivated the “Use hardware acceleration when available” option in my Firefox preferences, and in my Java VM options -Xms1024m and -Xmx2048m.

Updated the developer’s guide

I passed once more some hour or two with #40 (Improve technical documentation about Lino) and updated Specs.

A Lino course on PySpace?

Virgo invited me to create a Lino course on their Python learning platform https://pyspace.eu

The platform works using “challenges” where the course participant must upload a source code file which is then tested automatically. You get immediate feedback, and you can see the names of other participants who entered the hall of fame. Nice idea for motivating people to learn Python and (en passant) finding new employees!

Now how to integrate a Lino course into this system? I mean which question to ask so that a participant can meaningfully answer using a script to be uploaded and to be tested. Not yet sure. I have no concrete idea about how a Lino course on PySpace would look like, but it’s a good challenge and will certainly help Lino to grow.

But anyway, before writing a course I should test whether the instructions in Installing a Lino developer environment work. And oops of course they don’t.

Installing Lino using pip under Python 3

I opened #2765 and started to fix the problems.

I released Lino Così 18.12.0 because of course the August 2018 version would certainly not collaborate with the December version of Lino.

Appy is not being installed automatically under Python 3.

While trying to find a solution for this, I found django-appypod and inspected their setup.py. And –cool!– they obviously found my blog post Sunday, May 6, 2018 where I describe how to add appy under Python by adding it to a requirements file. And –even cooler!– they found how to integrate this into the setup.py file using dependency_links. I tried this for Lino and released 2018-12-18 and a follow-up version 18.12.5. But couldn’t get it to work. Similar problem as the one reported here.

Will ask Hamza to work on it.

Summary

All above is what our customers call “general framework development”, and they explicitly do not want to pay us for doing this work. IOW today I haven’t done any productive work. As Hannes formulated already 10 years ago: “You work on Lino just for fun and in the same way as others sing in a choir.” There is a lot of work waiting for which I would get paid, and “general framework development” should be of lower priority.

So why am I doing this? Why does Rumma & Ko pay me and Hamza and Tonis for doing “general framework development”? Our only answer is that we “believe” in Lino…