0.5.22: Bugfixes, Ubuntu 20.04 dropped

[adamkewley]

0.5.22 is primarily a bugfix release, the biggest changes are:

• It drops support for Ubuntu 20.04: Ubuntu 20.04 LTS ended 23rd April 2025, which means that other systems (e.g. GitHub actions, which OSC uses to build releases) no longer support it.
• It internally handles file dialogs differently (it now uses SDL3, which decouples it from GTK on Linux). This means that the file dialogs will behave a little bit differently, please report any issues.
• OpenSim::Forces now expose their records (e.g. OpenSim::Force::getRecordLabels) as plottable/watchable outputs, which makes (e.g.) debugging forces easier.

The most important bugfixes are:

• The is_visible flags on Appearance editors now work again (Fix is_visible and "show/hide" for ContactGeometry does not hide the geometry #1028).
• Plotting two 1D outputs in a 2D plot was fixed (previously, it was always plotting the first against itself, Fix two dimensional output plot (phase plot) plots X against X #1025)

See CHANGELOG.md for more details

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This discussion was created from the release 0.5.22: Bugfixes, Ubuntu 20.04 dropped.

[JPi2323]

Thanks for all your great work Adam

[itbellix]

@adamkewley, just a quick note as an Ubuntu 20.04 user. I have installed a newer release (the latest today, 0.5.25): everything went smoothly, installation apparently succeeded, but then OSC would not open - but no error messages/warnings were thrown. I was just wondering if it is easy to implement also a way to warn the user for why this happens.

[adamkewley]

@itbellix , you can run osc from the command-line, which will print any bootup errors to the console.

The issue is probably that it cannot find certain symbols in the C++ standard library (libstdc++.so). The reason why is because OSC dropped Ubuntu 20.04 support in 0.5.22 as Ubuntu 20.04 went out of service for free users in May 2025 (Ubuntu lifecycle).

Although Canonical supplies paid-for extended support until 2030, third-party services (e.g. GitHub actions, my personal build server) stick to the freely-supported version.

OpenSim Creator's documentation outlines the currently-supported operating systems here. There are some tricks available for backporting libraries (e.g. using a newer C++ library with an older OS) but handling that for various configurations of Linux gets tricky.

[itbellix]

Okay, clear thank you! Indeed, I did not try booting it from the command-line, so it would just not launch. Reverting to an earlier version of course works fine, thanks ;)