Package: pypy3-dev Version: 7.3.5+dfsg-2 The import.h header file contains three #if-type directives and four #endifs which makes builds including that file fail as would been expected with unmatched #if-blocks.
Judging from a casual read the #endif in line 21 is the wrong one, and it worked for me to comment it out. Thanks and best regards Morten

