anchor.diff:  
     nativeBuildInputs = [
       cffi
  -    pkgconfig
  -    # somehow propagating from pkgconfig does not work
  -    pkg-config
  +    pkgconfig # this is the python module
  +    pkg-config # this is the actual pkg-config tool
       setuptools-scm
     ];
   
  
positive.code:     cffi
      asn1crypto
      cryptography
    ];
  
    # https://github.com/tpm2-software/tpm2-pytss/issues/341
  
negative.code: , cffi
  , cryptography
  , ibm-sw-tpm2
  , pkgconfig # see nativeBuildInputs
  , pkg-config # see nativeBuildInputs
  , pycparser
  , pytestCheckHook
  , python
  , pyyaml
  , setuptools-scm
  , tpm2-tss
  }:
  