---
name: DIALS core meeting 2026-02-26
tags: core meeting
---

# DIALS core meeting 2026-02-26

## Previous Actions

- [ ] **ND** Investigate getting `psana` tests running on the DIALS xfel-regression testing
- [x] **ND**: Move dials.diamond.ac.uk to a redirect to dials.github.io

## Agenda

### DIALS v3.27 released
- Mac missing, relying on conda-forge for now. Will accelerate installer replacement now as has become urgent.

### Other CI Issues
- Installers failing on our internal CI machines. Down to launch logic in https://github.com/dials/dials/blob/e91f5f66368ec546b160ccfd2fbd30b2926a65de/installer/create_installer.py#L36-L52 that prefers python2.7 if available - looks like conda-pack switched to requiring python 3.
- Probably easiest way for now is to just use `python`/`python3` and remove the fallbacks.
- 31/36 xfel-regression tests failing with errors like "/bin/sh: 1: cctbx.xfel.time_varying_refinement: not found". So some build issue there? Help please?

### Proposal for dials issue categorisation/management. (JBE)

JBE: I was thinking about how to organise the github issues and would like to give people chance to raise objections/feedback before going ahead. Discussed at Diamond Dials meeting, general agreement there.

- Using github issues labels and/or types, categorise tickets into one of 3 categories: bug, enhancement/feature, or discussion/question. Discussion/question issues can optionally be converted to github discussions (but does anyone look at these)? Bugs are software problems/crashes. Features are feature requests/suggestions. Discussions are user questions or nuanced long discussions on algorithms.
- Have a github project board each for bugs and features.
- On the project boards, classify each ticket using the idea of a 3x3 impact-effort matrix. Impact classification: high, medium, low. Effort classification: difficult (1>week), medium (~day), low (<1hr).

How we would use this.
- After 2+ weeks of a ticket being opened (to give time for initial discussion/external user input) we categorise and classify any new uncategorised issues (At the Tuesday Diamond DIALS meeting and/or Thursday dials-core).
- JBE volunteers to go through historical backlog to classify, or can organise an issue triage meeting(s).
- Use the impact-effort ratings to bring up selected issues for discussion at regular dials meetings with a view to reducing the backlog of most critical issues over time. Helps us to prioritise fixing real bugs.
- Issue fixing will continue to remain a voluntary process: issues **are not** going to be blindly assigned to people, we all have other priorities.

### dials.github.io
- Mac installer link broken
- ND to look into, currently macos tests failing causing the development build not to be deployed
- https://github.com/cctbx/cctbx_project/issues/1119
- Fixed in Feburary 2026 release 2026.1
- [ ] ND: Make sure this fixes issue

### Metrics

- 2025-09-25 - dxtbx-side merged in, nothing yet in DIALS side to push it into the mtz history https://github.com/cctbx/dxtbx/pull/816
- Needs to be work to put in on DIALS side
- Work to do:
- Need to package history into MTZ, but MTZ history not the right place. Decided MTZ-appendix is the right place to put this in, but work not started yet
- Aaron has offered Yang's skills as his work should cover this area
- [ Write integrate and scale history to MTZ #2924 ](https://github.com/dials/dials/pull/2924)
- David to dig relevant information out
- MTZ Appendix: Some controversy
- Phenix/DIALS not included in discussions
- Fundamental technological issues
- Mixing MTZ/CIF
- Gemmi supports
- AB met with BP/DGW/Oleg/Dorothy and talking about MTZ appendix issue
- Conclusion: Nobody completely happy, AB to approach Clemens and get conversation going
- Dan Paley found issue with profiling and MTZ appendix https://github.com/cctbx/dxtbx/pull/867
- Agreed looks reasonable
- Requested David to have a look

### AOAOB

- Probably table for new year
- It is now new year
- Hamburg: imageset, sequences, laziness so it works on 100,000 image HDF5 files
- Did some work in a branch to get stills_process to use imagesequences
- Nick did some work to eliminate need for check_format
- All of this is in branches that have not been revisited
- Discussion about still goniometer dogma

### ImageSequence vs ImageSet
- Marko is working on an NXmx-like format class for SerialED, where the beam position changes each image
- It seems not possible to use `ImageSequence` for this, as it does not allow different models per image. Is this correct?
- `ImageSet` works, but import and viewing images is much slower
- Is there a long term plan to converge to just one of these classes, with all performance and feature issues fixed?
- Suggestion to look at DMcD properties table
- Discussion about serialization/deserialization overhead, brief discussion of using another form e.g. hdf5 or sqlite (for Experiment Lists).
- Discussion of existing uses of mixin inheritance

### APS Workshop

- ~~This did not get support from APS => not happening (APS UM workshop, )~~
- ~~GW had conversation about expanding workshop scope. Was half-day, thought maybe a full day - scope expanded to e.g. serial processing ~~
- ~~APS User meeting: May 4th-8th 2026 two half-days of DIALS workshop probably~~
- ~~Some travel funding available, potentially from outside US~~
- ~~Proposal submitted, no reply yet, probably not before Christmas~~
- CCP4 workshop _is_ happening APS
- AB says RAPIdata also approached us about DIALS workshops there - GW believes AB/DP covering

### New issues for discussion
- https://github.com/dials/dials/issues/3115 Publication categories on webpage, also related PR 3114
- https://github.com/dials/dials/issues/3110 dials.index with max_lattices >= 2: rejection criteria.

### Other

- Webinars: GW did one yesterday for NSLSII, requests for a couple more...
- ED, xia2.ssx and stills_process requests
- JBE happy to approach
- Chat to DGW about ED
- Dan nominated by AB to prepare for stills_process
- GW to email, coordinate
- GW Emailed Vivian, JBE looped in and aware.
- Discussion ongoing, people on top of

- ND to investigate effort required for installer build issue resolution
- Investigated basic, infrastructure still fails to identify macOS arm, still need to proceed with conda-based installer plan

- xfel regression testing of https://github.com/dials/dials/pull/3062 (cosym performance changes) JBE asking for help please. Also somewhat unrelated, regular failing of CI jobs due to http download errors?
- We should turn off regression tests
- Maybe explore gitlab LFS as it works well for xfel-regression

- IUCR: AB putting schedule together for DIALS workshop, wondering who is going to be attending, for scheduling speakers. 8am-Noon
- Need answers by Feb 15th

## AOB

### Next meeting

Due to time zone changes the normal meeting time must change:

Thursday, March 12th, 4pm (GMT), 9am (PDT), 11am (CDT)

or

Thursday, March 12th, 3pm (GMT), 8am (PDT), 10am (CDT)