Export to PNG gives error on Raspberry Pi?

Questions
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1

Dear Wolfram Community,

for some time now I observe the following issue under Wolfram installed within a docker container on a Raspberry Pi.
When I try to export something to png, e.g.,

Export["test.png", Plot[x, {x, 0, 1}]]

I get

Import::fmterr: Cannot import data as PNG format.

On the other hand I can export to, e.g., jpg just fine. Moreover, I can import png images without problems.

Some information on my environment:

The Wolfram engine is installed in a Docker container running on a Raspberry Pi 4 with Ubuntu 20.04.
I tried different base images which both showed the same above described behavior:

  • the official python:3.10-bullseye container, where I added the deb
    http://archive.raspberrypi.org/debian bullseye main
    and added the armhf architecture to dpkg before installing the wolfram-engine package.
    (This setup did already work in the past, but at some point a rebuild of the image must have broken things, which I didn’t realize as I did not export to png for some time.)
  • the image navikey/raspbian-bullseye where I just added the armhf architecture to dpkg and then installed the wolfram-engine package.

Can somebody else reproduce this problem or has a hint on what I’m doing wrong.

Thanks and Best Regards,
Dominik

2

I can confirm the problem. This is a problem for Mathematica 12.2 and 12.3.
Version 12.1 can export PNG files without problems.It has nothing to do whether you use bullseye or buster or other systems on Raspberry Pi. The problem must be in the implementation of Mathematica for raspberry pi for versions 12.2+.
Unfortunately this also means the Mathematica-jupyter kernel provided by WolframLanguageForJupyter-paclet does not work properly as it uses PNG format to export results to jupyter notebook. (No graphs are displayed)

3

Thanks for confirming the problem.

As a matter of fact, the problem with the WLFJ paclet was also the way that I discovered that problem. I posted an Issue in the corresponding Github repo. And according to a response by a Wolfram Research team member the problem is now under investigation.

Maybe we have luck and this is fixed in the next minor release.

4

Fortunately, the PNG problem is fixed in the Raspberry Pi implementation of version 13.0. Now exporting to PNG works, which means the WLFJ-paclet also works!

5

I can confirm that this is really the case. This affects Mathematica 12.2 and 13. Version 12.1 can export PNG files. The employment of bullseye, buster, or other systems on Raspberry Pi is irrelevant. The issue must be in Mathematica Krunker for Raspberry Pi 12.2+. A problem arises while using the Mathematica-Jupyter kernel offered by WolframLanguageForJupyter-paclet. (No graphs shown)