Package: libswiften-dev
Version: 5.0~alpha2.145.g12d031cf8+dfsg-2
Severity: normal
/usr/include/Swiften/Version.h contains
#define SWIFTEN_VERSION 0x000000
#define SWIFTEN_VERSION_STRING "20221024"
instead of the version number…
This breaks a version check in spectrum2…