Online Developer Meeting (2022-02-22)

• Date: Tuesday, Feburary 22, 2022 @ 18:00 UTC
• Location: https://meet.jit.si/octave-dev

Todays topics

• Meet and greet 5 minutes before meeting (audio testing).

Release process of Octave 7.1

• Blocking issues: 9 bugs targeting 7.0.90, 3 marked as "ready for test" (see Savannah overview on octave.space)
• Good progress on some of the blocking issues by jwe. Most important remaining ones:
  • bug #61788: arrays of type int16 contain wrong numbers
    • The :-operator will probably be changed to return an array (instead of a range object) before Octave 7. Not started yet.
  • bug #61813: memory management bug when calling MEX that returns an output
    • @jwe provided an initial changeset. That will also revert to copying data in the .mex interface (less efficient) unless Octave is compiled with C++17 pmr.
  • bug #61821: segfault using tree_parameter_list in oct file
    • Lower priority, only 32-bit (only on Windows?). Probably not a blocker.
  • bug #61898: subsref: Error when field syntax is used on non-scalar @class object
    • Not a bug in Octave core. Recent changes to output argument validation uncovered an issue in interval package.
  • Similar bug #61843: Regression with subscripted assignments with arrays of objects
    • Older regression.
  • Use suffix for API string when it requires C++17 pmr?

Minimum Qt5 version for Octave 8?

• See Qt5.15 already unsupported upstream (except commercial license)?

Previous topics

The following items were not discussed. Just some links to progress on those items are displayed.

Release process of Octave 7.1

• Blocking issues: 9 bugs targeting 7.0.90 (see Savannah overview on octave.space)
• Most important ones (in no particular order):
  • bug #61788: arrays of type int16 contain wrong numbers
    • The :-operator will probably be changed to return an array (instead of a range object) before Octave 7.
  • bug #61813: memory management bug when calling MEX that returns an output
    • Probably caused by changes for more efficient data interface for .mex files. @jwe will check this.
  • Possible issues if Octave is compiled with C++17 (--enable-pmr-polymorphic-allocator), while .oct files are not.
    • Maybe change the API string if Octave is configured with polymorphic allocators?
    • Leave that option in. But disable it by default. (That is already the current state.)
  • malloc-delete[] combination in the .mex interface
    • No decision made. Maybe leave as is?
  • bug #61821: segfault using tree_parameter_list in oct file
    • Check if we are doing something wrong for 32bit. Probably not a blocker.
  • bug #61898: subsref: Error when field syntax is used on non-scalar @class object
    • Try finding a minimal reproducer (without interval package). Similar bug #61843 reported.
• A few package releases with fixes for Octave 7 were pushed to the default branch of MXE Octave, e.g. https://hg.octave.org/mxe-octave/rev/d601436d29f2 (ga, control, communications)
  • Should those changes be grafted to the "release" branch? -YES.
• Revisit load path caching: https://octave.discourse.group/t/rfc-remove-faulty-load-path-caching/2136
  • Improving the caching strategy is the way to go (see e.g. bug #54636).
  • Long-term: A complete overhaul of the load path caching implementation is probably necessary.

C++17 features in Octave API?

• Timeframe?
  • When qt6 is distributed? - Probably bad strategy (Debian/Ubuntu and even Arch have trouble with qt6).
  • Regarding stable=stale Linux distributions.
• Should we announce that possible requirement for some time in the future with the release of Octave 7?
• See also: Should Octave switch to C++17? If so, when? on Discourse.
• We'll start an experiment by enabling polymorphic allocators for default Octave on the default branch of MXE Octave. We'll evaluate if the necessary changes to dependent packages are trivial.

GSOC 2022 opening soon

• In this wiki GSoC (landing page) and Summer of Code (past projects).

• GSOC 2022 Timeline (Feb 7-21 is Org application window, acceptances announced Mar 7.)
• 2022 changes - after shifting to shorter projects in 2021, GSOC now allows flexible project/time commitments from 10-22 wks (12 standard, org/mentor flexibility on milestone dates).
• GSOC FAQ (took note that the organization does get a small stipend for participating... helping a bit to offset yearly infrastructure costs)
• Past projects at other orgs ranged quite widely in scope, especially with change to smaller projects in 2021:
  • some were often a part of big tasks. Are there bigger octave goals that could be parted out for a GSOC task? parts of classdef, or graphics handles, or a new command window, or dare we suggest JIT?
  • Some amounted to "tackle all the bugs related to X". Are there bug categories or unimplemented function categories (that might require particular coding or mathematical knowledge) worth directing particular focus on? 'the unimplemented interpolant classes/functions' or 'unimplemented image package functions related to feature recognition' or ...
  • "complete this unfinished thing" tasks (prior gsoc? pkg related? the 'did you mean' feature?)
• Thinking ahead, 'Google Season of Docs' has typically announced/opened their program in Feb-March. Are there small/large doc projects worth getting into GSOD so a paid freelance technical writer/coder can take it on for 6-9 months? Successful examples ranging from document creation to doc infrastructure - 2021 2020 2019
• Please find small / partial contributions (also m-files) that help you with your current projects on Octave.
  • HDF5 project?
  • Time to specify the task lacks...

See also

• Next meeting: Online Developer Meeting (2022-03-22)
• Last meeting: Online Developer Meeting (2022-01-25)