axicli – XMLSyntaxError: Blank needed here

[Chris D]

Hi

I’m trying to use axicli to create a ‘plob’, but it gives an error that seems to mean that the SVG is invalid.

I used Inkscape to create a very simple SVG file, which works fine in preview mode (with ‘–preview’), but with ‘–digest 2 -o output_plob.svg’ it gives a long traceback ending with

lxml.etree.XMLSyntaxError: Blank needed here, line 1, column 21

The SVG file starts with

<?xml version=”1.0″ encoding=”UTF-8″ standalone=”no”?>
<!– Created with Inkscape (http://www.inkscape.org/) –>
…

I’m using AxiDraw Command Line Interface 3.9.6, AxiDraw Software 3.9.6, Python 3.11 on Arch Linux.

I can supply all the gory details if required. Has anyone else seen this issue?

Cheers,

Chris

[Windell Oskay]

I am able to reproduce the issue, and I will look into it.

[Windell Oskay]

This appears to be due to a bug in the latest release of lxml.

Try: python3 -m pip uninstall lxml

Then, python3 -m pip install lxml==4.9.4

[Chris D]

Thanks for your reply. You’re probably right, but I’m struggling with versions of Python libraries: the ‘EXTERNALLY-MANAGED’ feature of pip (see e.g. https://bbs.archlinux.org/viewtopic.php?id=286788) means that I have to install everything that AxiDraw needs in a new Python virtual environment using pipx, and that insists on giving me the latest version of lxml (5.1), so I’m still seeing the error.

I’ll report back once I’ve got my head round this Python library versioning mystery.

[Windell Oskay]

Hmm. We don’t have experience with pipx, so I’m not sure why that’s requiring a specific lxml version.

We’re planning to pin the lxml requirement in the next point release unless they fix that upstream.

[Chris D]

Aha! I just had to edit AxiDraw’s setup.py to change

‘lxml>=4.9.3’,

to

‘lxml==4.9.3’,

Then I just ran

pipx install .

and it’s all working again.

Trying to specify the lxml version on the pipx command line didn’t work.

[Windell Oskay]

Great. That’s the type of change that we are planning for the software if the upstream bug doesn’t get resolved promptly.

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