Thank you , it helps . step 3 - python3 setup.build * gets a fatal error on the include file; FYI python3 is mapped to python3.13.8 I am not certain if this include file needed for build is available for this version of python ? I may have to revert to an older version if workaround is not available.
Kwant/_system.c:222:12: fatal error: longintrepr.h: No such file or directory
222 | #include "longintrepr.h"
| ^~~~~~~~~~~~~~~
compilation terminated.
