ChimeraX Developer Meeting

Attendance: Zach, Eric, Tom, Greg

March 16, 2026

Agenda

• PySide, any new bugs?
• PyQt license allows distributing old ChimeraX after license expires?
• Toolshed update caching to reduce database load.
• Chimera not working with macOS 26, graphics pane positioned over command-line.
• Work in progress reports
• Inside ribbon color?
• Make Chimera end-of-life bug report and registration changes.

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Discussion

• PyQt licensing
  • If we do not renew our PyQt license in April can we continue to distribute older ChimeraX versions with PyQt?
  • The ​Riverbank license page seems to say yes: "A license is perpetual so you may continue to use the versions covered by the license for ever."
  • Even if PySide problems caused us to use PyQt in the June 2026 ChimeraX release we could use the current PyQt 6.10.2 (or soon to be out 6.10.3).

• PySide crashes not at exit
  • Elaine reported a ChimeraX crash that appears to be a crash at exit, but she says she was not exiting.
  • We have seen several of these reported and incorrectly assumed they were crash when the user quits.
  • Could be PySide or Qt 6.10 is catching signals and trying to clean up masking the real cause of the crash.
  • Elaine says she was modifying auto-scrollbar display in Mac settings, and was not even in ChimeraX when it crashed. Had Profile Grid shown which uses scrollbars.
  • Also saw more than 10 of these crashes summer of 2025 during a PySide trial in the daily build with Qt 6.9. That supports the theory that PySide is the cause of the clean up, since ChimeraX 1.11 uses Qt 6.9 and we do not see crash reports like this.

• Toolshed caching
  • Next step to improve Toolshed update query performance is Greg will look at reducing data returned by query.

• Claude code
  • Eric watched 3 Phenix developer workshop talks by Zoom and Tom 1 and all were about using Claude to write code or for user control of software.
  • Tom Terwilliger talked about an AI Agent for running Phenix refinements.
  • Matthew Baker talked about new cryoEM structure determination tools written using Claude.
  • Vincent Chen talked about Molprobity Next written using Claude.

• GPU nodes
  • Greg will install Rocky 10 on 3 GPU nodes. Does not need to wait for internet connectivity since he has Rocky 10 installer on portable NVMe drive.
  • Network connectivity is waiting on Cisco switch being programmed for bonded connections to plato. Tom Ferrin wants to hire Josh to set that up. Not sure how hard that will be, given Josh is on leave and probably sanctioned by UCSF IT.

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Action Items