"Ambiguous declaration" build failure(s) — clang 9.0.1

PackageVersionSupposed error messageFull log Bug report
fim 0.5.3-2FbiStuffJpeg.cpp:181:36: error: use of overloaded operator '+' is ambiguous (with operand types 'fim::string' and 'const fim_char_t *' (aka 'const char *')) Log
igor 1.3.0+dfsg-1Deletion.cpp:909:60: error: use of overloaded operator '+' is ambiguous (with operand types 'const char [30]' and 'Seq_side') Log
libfreesrp 0.3.0-2freesrp_impl.cpp:31:39: error: reference to 'FreeSRP' is ambiguous Log
plee-the-bear 0.6.0-6model_action.cpp:399:50: error: use of overloaded operator '>' is ambiguous (with operand types 'claw::real_number' (aka 'real_number') and 'bear::universe::time_type' (aka 'double')) Log

4 errors