Steps to install leo using pip in python 3.5

[Brian Theado]

On Ubuntu 16.04 with python 3.5, I tried installing leo into a virtual env using these commands:

$ python3 -m venv leo-editor-venv
$ cd leo-editor-venv
$ bin/pip install leo

When I run leo, I get this error

$ bin/leo
leoQt.py: can not fully import PyQt5.
Traceback (most recent call last):
  File "bin/leo", line 7, in <module>
    from leo.core.runLeo import run
  File "[...]/leo-editor-venv/lib/python3.5/site-packages/leo/core/runLeo.py", line 27, in <module>
    leoGlobals.app = leoApp.LeoApp()
  File "[...]/leo-editor-venv/lib/python3.5/site-packages/leo/core/leoApp.py", line 324, in __init__
    import leo.core.leoFrame as leoFrame
  File "[...]/leo-editor-venv/lib/python3.5/site-packages/leo/core/leoFrame.py", line 13, in <module>
    import leo.core.leoColorizer as leoColorizer
  File "[...]/leo-editor-venv/lib/python3.5/site-packages/leo/core/leoColorizer.py", line 9, in <module>
    from leo.core.leoQt import Qsci, QtGui, QtWidgets # isQt5, QtCore
  File "[...]/leo-editor-venv/lib/python3.5/site-packages/leo/core/leoQt.py", line 76, in <module>
    qt_version = QtCore.QT_VERSION_STR
NameError: name 'QtCore' is not defined

After some investigaton, I see that leo's exception handling is hiding the real error message. I used pdb to find it:

$ bin/python -m pdb  bin/leo
(Pdb) break leo/core/leoQt.py:20

Then stepping line-by-line leads to this at line 53:

 53  ->         from PyQt5 import QtCore
ImportError: [...]/leo-editor-venv/lib/python3.5/site-packages/PyQt5/QtCore.so: undefined symbol: PySlice_AdjustIndices

Searching for that error message leads to these links, which point the finger at the latest PyQt wheel not being compatible with python 3.5:

https://github.com/mu-editor/mu/issues/502#issuecomment-399682079
https://github.com/mu-editor/mu/issues/538#issuecomment-404096351
"Chipping in rather late: the error message in the OP refers to a Python API that was only added in 3.6.1. Since the venv is using Python 3.5 it appears that Qt have offered a wheel for 3.5 which uses code only available in 3.6"

Here's the version of PyQt which pip installed in my virtual environment:

$ bin/pip freeze | grep PyQt5==

PyQt5==5.11.2

I tried version 5.10.1 of PyQt but got a different error; however, verson 5.10.0 seems to work.

$ bin/pip install PyQt5==5.10.0

In summary, these steps can lead to a working leo virtual env install from pip on python 3.5:

$ python3 -m venv leo-editor-venv

$ cd leo-editor-venv

$ bin/pip install leo

$ bin/pip install PyQt5==5.10.0

$ bin/leo

It's very nice that leo and its dependencies can now be install via pip on Linux. Clearly there are still some gotchas, but it can work!

Brian

[Matt Wilkie]

I tried version 5.10.1 of PyQt but got a different error; however, verson 5.10.0 seems to work.

$ bin/pip install PyQt5==5.10.0

[...]

 

It's very nice that leo and its dependencies can now be install via pip on Linux. Clearly there are still some gotchas, but it can work!

Thank you for this clear write up! If you have time please open an issue in the Github tracker and tag it 'pip'. Looks like we should be specifying version numbers.

Matt

[Brian Theado]

I created this issue: https://github.com/leo-editor/leo-editor/issues/944, but I didn't see a way to tag it.

--
You received this message because you are subscribed to the Google Groups "leo-editor" group.
To unsubscribe from this group and stop receiving emails from it, send an email to leo-editor+...@googlegroups.com.
To post to this group, send email to leo-e...@googlegroups.com.
Visit this group at https://groups.google.com/group/leo-editor.
For more options, visit https://groups.google.com/d/optout.

[Edward K. Ream]

On Tue, Jul 17, 2018 at 9:09 PM, Brian Theado <brian....@gmail.com> wrote:

I created this issue: https://github.com/leo-editor/leo-editor/issues/944, but I didn't see a way to tag it.

I've added some tags.

Edward

[Brian Theado]

I've found this setup will give a segfault when the python_terminal plugin is enabled. Using gdb, I see it is almost the same crash already reported by Chris George a while back: https://groups.google.com/forum/#!topic/leo-editor/6EVF4Rw8o_I. In his case he was using Ubuntu 16.04 with python 3.5 and PyQT 5.7. My setup is the same, except with PyQt 5.10.0.

[...]
0x00007fffdc77e3e1 in rl_initialize () from /usr/lib/x86_64-linux-gnu/libedit.so.2

[...]

Some ways I've found this crash does not happen:

1. Avoid python 3.5 + PyQT
1. use conda or some other method to get different version of python
2. use more recent version of ubuntu which comes with python 3.6+. Ubuntu 16.04 is getting old, but it will be a supported release for years to come.
2. Disable python_terminal plugin
3. Use the --nosplash command line option
4. Run python with '-m pdb' and then 'c' at the pdb prompt (I was doing this to troubleshoot the issue and of course the problem didn't happen)

I have no idea why #3 helps. I think #4 might help because pdb loads readline which somehow prevents the later readline crash when python_terminal loads.

I added this to launchLeo.py to get the python trace at the segfault:

import faulthandler; faulthandler.enable()

which gave this:

Leo 5.7.4 devel, build 20180815095610, Wed, Aug 15, 2018  9:56:10 AM

Git repo info: branch = devel, commit = 9db824eb3746

Python 3.5.2, PyQt version 5.10.0

linux

** isPython3: True

Fatal Python error: Segmentation fault

Current thread 0x00007fc6d6d53700 (most recent call first):

  File "<frozen importlib._bootstrap>", line 222 in _call_with_frames_removed

  File "<frozen importlib._bootstrap_external>", line 906 in create_module

  File "<frozen importlib._bootstrap>", line 577 in module_from_spec

  File "<frozen importlib._bootstrap>", line 666 in _load_unlocked

  File "<frozen importlib._bootstrap>", line 958 in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 969 in _find_and_load

  File "/usr/lib/python3.5/rlcompleter.py", line 174 in <module>

  File "<frozen importlib._bootstrap>", line 222 in _call_with_frames_removed

  File "<frozen importlib._bootstrap_external>", line 665 in exec_module

  File "<frozen importlib._bootstrap>", line 673 in _load_unlocked

  File "<frozen importlib._bootstrap>", line 958 in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 969 in _find_and_load

  File "[...]/leo-editor/leo/plugins/python_terminal.py", line 52 in <module>

  File "<frozen importlib._bootstrap>", line 222 in _call_with_frames_removed

  File "<frozen importlib._bootstrap_external>", line 665 in exec_module

  File "<frozen importlib._bootstrap>", line 673 in _load_unlocked

  File "<frozen importlib._bootstrap>", line 958 in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 969 in _find_and_load

  File "[...]/leo-editor/leo/core/leoPlugins.py", line 516 in loadOnePluginHelper

  File "[...]/leo-editor/leo/core/leoPlugins.py", line 563 in loadOnePlugin

  File "[...]/leo-editor/leo/core/leoPlugins.py", line 457 in loadHandlers

  File "[...]/leo-editor/leo/core/leoPlugins.py", line 338 in doPlugins

  File "[...]/leo-editor/leo/core/leoGlobals.py", line 5016 in doHook

  File "[...]/leo-editor/leo/core/leoApp.py", line 2219 in load

  File "[...]/leo-editor/leo/core/runLeo.py", line 72 in run

  File "[...]/leo-editor/launchLeo.py", line 9 in <module>

Segmentation fault (core dumped)

Even if I sidestep the crash using #3 above, I can get a similar readline related crash by running the unitTests. This time, loading the pdb module is crashing:

Leo 5.7.4 devel, build 20180807122609, Tue Aug  7 12:26:09 CDT 2018

Git repo info: branch = devel, commit = 532eda4fd138

Python 3.5.2, PyQt version 5.10.0

linux

** isPython3: True

reading settings in /leo/leo/test/unitTest.leo

found  2 doctests for leo.core.leoGlobals

found  1 doctests for leo.core.leoTest

Fatal Python error: Segmentation fault

Current thread 0x00007f74a2411700 (most recent call first):

  File "<frozen importlib._bootstrap>", line 222 in _call_with_frames_removed

  File "<frozen importlib._bootstrap_external>", line 906 in create_module

  File "<frozen importlib._bootstrap>", line 577 in module_from_spec

  File "<frozen importlib._bootstrap>", line 666 in _load_unlocked

  File "<frozen importlib._bootstrap>", line 958 in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 969 in _find_and_load

  File "/usr/lib/python3.5/pdb.py", line 151 in __init__

  File "/usr/lib/python3.5/doctest.py", line 357 in __init__

  File "/usr/lib/python3.5/doctest.py", line 1453 in run

  File "/usr/lib/python3.5/doctest.py", line 2185 in runTest

  File "/usr/lib/python3.5/unittest/case.py", line 600 in run

  File "/usr/lib/python3.5/unittest/case.py", line 648 in __call__

  File "/usr/lib/python3.5/unittest/suite.py", line 122 in run

  File "/usr/lib/python3.5/unittest/suite.py", line 84 in __call__

  File "/usr/lib/python3.5/unittest/suite.py", line 122 in run

  File "/usr/lib/python3.5/unittest/suite.py", line 84 in __call__

  File "/usr/lib/python3.5/unittest/suite.py", line 122 in run

  File "/usr/lib/python3.5/unittest/suite.py", line 84 in __call__

  File "/usr/lib/python3.5/unittest/runner.py", line 176 in run

  File "/leo/leo/core/leoTest.py", line 659 in doTests

  File "/leo/leo/commands/debugCommands.py", line 185 in runSelectedUnitTestsLocally

  File "/leo/leo/core/leoGlobals.py", line 320 in new_cmd_wrapper

  File "/leo/leo/core/leoCommands.py", line 2071 in executeAnyCommand

  File "/leo/leo/core/leoCommands.py", line 2042 in doCommand

  File "/leo/leo/core/leoKeys.py", line 3677 in masterCommand

  File "/leo/leo/core/leoKeys.py", line 3115 in doBinding

  File "/leo/leo/core/leoKeys.py", line 3068 in masterKeyHandler

  File "/leo/leo/plugins/qt_events.py", line 90 in eventFilter

  File "/leo/leo/plugins/qt_gui.py", line 1130 in runMainLoop

  File "/leo/leo/core/leoApp.py", line 2235 in load

  File "/leo/leo/core/runLeo.py", line 72 in run

  File "/leo/launchLeo.py", line 9 in <module>

Segmentation fault (core dumped)

Hope this helps others if they run into this issue.

[Terry Brown]

On Thu, 16 Aug 2018 21:45:58 -0400
Brian Theado <brian....@gmail.com> wrote:

> • Disable python_terminal plugin

Interesting, I'd noticed this too, playing with Docker images as test
install environments. It seems to be the line

from rlcompleter import Completer

but not that it necessarily fails to import, just that it causes
segfaults.

Cheers -Terry