Hello,

Please see below the meeting minutes for this week.

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Present: Steven Brandt, Maria Hamilton, Roland Haas, Atul Kedia, Pieter Diener, Bill Gabella, Eric Schnetter, Yosef Zlochower, Liu Haoyong, Zach Etienne, Antoni Ramos

Chair: Peter

Minutes: Maria

• Peter starts the meeting with the first item on the agenda: replacement of the cacuscode.org web page, and asked Seven to explain the situation.

Steven explained that that he wants a resolution to this this issue and will keep adding it to the agenda until it is resolved, and the old web page replaced.

Roland mentioned that Ian Hinder worked on a replacement for the web site, and gave the links:

https://test.cactuscode.org/ 

https://github.com/einsteintoolkit/cactuscode.org/issues

The problem is that there are about 30 or more things that need to be fixed and he asked for volunteers to help pushing things forward. 

Steven asked if is absolutely necessary to address each on of them or only the essential ones. 

Atul Kedia was interested in the location of the the new web page, and if all the information from the old web page will be kept. 

Steven encouraged Atul to take a look and compare the info, warning that the new web page will not have the same functionalities, not being written in php.

• Peter closed the first item and opened the second item on the agenda: virtual machines, and again, handed it over to Steven, to elaborate it. 

Steven explained his proposition to replace the old server to host the tutorial with a new one, because the current one is struggling, is fragile and complex.

Roland wanted to make sure that the new server has the same capabilities of creating and managing individual accounts, like the Kubernetes set up.

Steven assured him that JupyterHub is a better alternative to Kubernetes, and that multiple accounts can be managed.

• Peter went on to the third item on the agenda, namely the gcc 10 issues and yielded to Roland to explain his work in trying to fix it.

Roland related the problems with compile failure with gfortran 10 when using CCTK_PointerTo, and compiling LAPACK ExternalThorn from source tarball fails with gcc 10. He reporter that he has them almost fixed and will back port them to the current release. The problem with CCTK_Reduce is an old one, and it was reported since 2004 by Roberto de Pietri, and there is no fix. He proposed a change in the interface, namely in the Fortran function call, which will finally fix the issue.  

Peter commended Roland for his work, declaring that he is impressed.

Roland thanked and said that he wished the compiler would not have changed, because it worked before.

Zach reminded also about the compilation issue with Baikal, which is mystifying, it is not giving an error, it is just very slow. 

• Peter went on to the next item, namely call for reviewers for the proposed thorn additions for the next EKT release in 5 months. 

Zach offered to review Power, a wave-form extractor thorn, that will be polished and developed more this summer by a student under Roland's supervision. 

Maria tentatively offered to look into con2prim, a code developed by for a set of recovery schemes for primitive variables in GRMHD. 

Roland said that he will send more info about this, and that there is plenty of time for a decision to be made.

• Peter continued to the next item on the agenda, namely the work on the Binary Black Hole Gallery, and asked Atul about the status of the testing. 

Atul explained that to his understanding there is still ork to be done, and he will look into the scripts on the simulations sent by Ian Hinder. He also mentioned that Peter S., who was not in the meeting, had problems with running on the cluster in Germany. 

Roland explained that the problems appeared because the cluster is very new, uses python3 and hyperthreading, and it is difficult to set up. 

• Peter went on to ask about the status of the binary neutron stars gallery. 

Roland reported that Sean R. finished the simulations and obtained agreement before merger, but the post-merger is a little different, which was expected. He will re-run the simulation on his workstation, to confirm his suspicions that it depends on the compiler.  

• Peter asked for chair/minute volunteers for the next two weeks.

Roland expressed his hope that by July the meetings will be better attended because the new grant funds more people, and it will be easier to find volunteers.

•  Next, Peter went to unanswered issues and open tickets. Most were about gcc 10 which were already addressed by Roland previously. There was an issue with instability of Summation by parts, and Roland will look into it. 

• Peter adjourned the meeting.