Source: isospec Version: 2.0.2+dfsg1-3 Hi Maintainer
The file debian/control has Build-Depends on the following [1]: python-dev, python-setuptools, Please drop these, as no Python 2 module is built. Regards Graham [1] https://salsa.debian.org/debichem-team/isospec/-/blob/master/debian/control#L12-13