SUMMARY
Not really a bug but a compilation error which I managed to solve:

I compiled and installed the latest indi core, indi 3rdparty and stellarsolver from their respective git repos. I then pulled the latest kstars from the git repo as well and tried to rebuild kstars from scratch. However I was getting compilation errors like this:

In file included from .../kstars/kstars/indi/indicamera.cpp:7:
.../kstars/kstars/indi/indicamera.h:200:51: error: incomplete type ‘FITSData’ used in nested name specifier
  200 |         bool setFITSHeaders(const QList<FITSData::Record> &values);

A friend of mine did not encounter this problem but he is using a newer gcc. Mine is:
gcc (Ubuntu 11.4.0-1ubuntu1~22.04) 11.4.0
and his was:
gcc version 14.1.0 (Ubuntu 14.1.0-5ubuntu1

The workaround to this problem was to add:
#include "fitsviewer/fitsdata.h"
at the beginning of kstars/indi/indicamera.h

This allowed me to compile kstars as expected.