acts: Bug: Segmentation fault when calling GSF fitting from Athena

I’m currently doing refitting of ATLAS signle-electron tracks inside Athena (the ATLAS software environment) with the ACTS GSF, so calling the fit function of GSF.

Using a custom version of ACTS with Athena and doing several std::couts to see where the segmentation fault occurs, I have located the issue to this line: https://github.com/acts-project/acts/blob/v23.5.0/Core/include/Acts/TrackFitting/GaussianSumFitter.hpp#L288

Athena is currently using ACTS v23.5.0. I have also tried it with ACTS v23.5.0 + cherry-picking the following fixes I saw in v24:

• (#1927) (7f0429f)
• (#1933) (250ea03)
• (#1935) (0b9004f)
• (#1941) (58bb693)
• (#1963) (44eff4f)
• (#1970) (a6b3d6a)

The segmentation error still occurs, and at the same place.

[Bug]

Edit: typo

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Created a MM channel here: https://mattermost.web.cern.ch/acts/channels/bug-gsf-segfault