Segmentation Fault when converting to images

[charlesfsl]

Updated: to mention where the call to vega_lite_convert exists in the example repo.

Is there any additional setup to use this library, like some OS libraries to install? We discovered a segfault kept happening in CI when we would call VegaLite.Convert.to_svg(). We've since determined this happens reliably in Debian Bookworm and NixOS 24.11—we're currently using Debian Bookworm in Docker on CircleCI. We've not tested other distros. This isn't a problem in MacOS 15.2.

To work around this for now, we're using VegaLite.Export, which does not seem to have this issue but is also deprecated in favor of vega_lite_convert.

Testing other functions, these all cause a segmentation fault in both MacOS and Linux:

• to_png/2
• to_jpeg/2

However to_json/2 works fine on both OSs. I didn't test all conversion functions.

I've created a somewhat minimal repo that reproduces the issue: https://github.com/smartlogic/vega_lite_segfault. The no-graph-render branch removes the rendering and assigns part to show that the segfault is unrelated to rendering. The calls to vega_lite_convert are in VegaLiteSegfaultWeb.SegFaultExampleLive.Index.

Is there any additional info that would be useful?

[jonatanklosko]

Hey @charlesfsl! Can you share what is the Debian base image (with the price Elixir and Erlang versions)? Also, which architecture do you use?

[charlesfsl]

Hi @jonatanklosko! The Debian image used in CI is hexpm/elixir:1.17.3-erlang-27.0.1-debian-bookworm-20241202. The architectures are:

• MacOS: M3 Max (ARM)
• NixOS: Intel 12th Gen i7-1260p (x86-64)
• CircleCI/Debian: x86-64

Thanks

[jonatanklosko]

@charlesfsl thank you! I managed to reproduce it on a x86_64 machine and I reported the issue upstream in vega/vl-convert#206 :)

[charlesfsl]

Thanks @jonatanklosko . I'll keep an eye on that issue.