ROOT Team Meeting

32/1-A24 (CERN)



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Danilo Piparo (CERN)

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ROOT Team Meeting
Zoom Meeting ID
Axel Naumann
Alternative hosts
Lorenzo Moneta, Danilo Piparo, Vincenzo Eduardo Padulano, Bertrand Bellenot, Jakob Blomer, Enrico Guiraud
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ROOT meeting 12/02/2024

Notetaker: Florine


To anticipate for the nightlies in GitHub: You can look at the nightlies in GitHub by clicking on "Actions" -> "ROOT CI" and then filter on "Event" -> "Schedule". We should update this in the shifter documentation. It is possible to relaunch the build of any failing one, but not sure if you can specify any options, to be seen.

From LIM: ATLAS will use 6.28.12 soon (but not yet). The development branches look good. LHCb now uses 6.30.04.

Gerri will join the fixathon at the end of Tuesday and on Wednesday.

Shift handover

Nothing special, forum and issues have been assigned. Next shifter is Marta.

Meeting summaries


A workshop will be organised in April (1 day, at CERN). Experiments have been contacted.
Danilo: We should book a room for this ASAP.


Regarding the 2 GB limit: we have a way forward to circumvent this, without having to change the on-disk format of TFile. It is still in development, but seems promising. The idea is to split large objects over multiple TKeys.


Fixathon preparation

Walk through the introduction slides, to be presented by Marta.
We will schedule a few minutes on Tuesday morning for each team to decide what parts they could best work on and which issues to tackle.
Vincenzo: Does everyone have access to the Mattermost channel?
Danilo: No, you need a CERN account but we can manually invite those that need it.
JonasH: Making this extra effort seems like unnecessary overhead considering we will all be in the same room together.



Regarding the deprecation auto auto: will break a lot of unnamed old macros, we should wait with removing until ROOT 7. We will start issuing deprecation messages starting from ROOT 6.32.


Regarding the HEP-CCE RNTuple interface review: an estimated 6 months required for the review, with a midway "checkpoint" to notify us if any large changes would be needed to the interface.


Regarding building and distributing GPL/LGPL: If people want to use mathmore they need GSL and they need to know that we distribute it without.
Vassil: I would like to see an example where this was actually followed up in court/with lawsuits.
ACTION Danilo: Discuss with Axel the GPL/LGPL issues regarding distribution of ROOT, and how this has been done historically.


Regarding the topic of the CAT hackathon:
Danilo: Can we arrive at the Hackathon with something from the list already done? A viable option would be the addition of the requested fonts (Helvetica).
Olivier: Will look into it.


Additional point following previous discussion: We express on the website that we transfer copyright from whoever contributes code to ROOT to the project. I would rather we address this instead of the GPL/LGPL discussion.


We are requested by experiments to show the PoW status every quarter. Last year we delivered about 50%, this year we have more items.

ACTION everybody please make sure to update the status of PoW items in the sheet whenever applicable. Everyone should have access to the sheet (see Indico attachements to this meeting, will also be pinned in Shush).

Vassil: Do we really want to be bound by the supervision of the experiments? This might be a double-edged sword and we might be able to shoot ourselves in the foot with this.
Danilo: We can change the PoW table during the year, e.g. if something turns out to be not relevant anymore.
Vassil: We can present what we have done, but it's important for the experiments to also realize we have other clients that are important to us.
Danilo: The main point of this exercise is that we don't want to have any bad surprises when we evaluate the PoW in November.

There are minutes attached to this event. Show them.
    • 4:00 PM 4:01 PM
      Find notetaker 1m
    • 4:01 PM 4:05 PM
      News 4m
    • 4:05 PM 4:10 PM
      Shift handover 5m
    • 4:10 PM 4:20 PM
      Meeting Summaries and Plans 10m
      • I/O
      • TMVA
      • RooFit
      • PPP
      • Planning / Godparents /...
      • LIM
    • 5:00 PM 5:25 PM
      Round Table 25m
    • 5:25 PM 5:30 PM
      A.O.B. 5m