https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86588
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> --- The error message for "-std=gnu++17 -fconcepts" case: In file included from /home/mi/h4nn3s/devel/seqan3/include/seqan3/range/view/take_line.hpp:46, from test.cpp:1: /home/mi/h4nn3s/devel/seqan3/include/seqan3/core/metafunction/range.hpp:218:8: error: partial specialization ‘struct seqan3::innermost_value_type<t>’ does not specialize any template arguments and is not more constrained than the primary template; to define the primary template, remove the template argument list /home/mi/h4nn3s/devel/seqan3/include/seqan3/core/metafunction/range.hpp:205:8: note: primary template here In file included from /home/mi/h4nn3s/devel/seqan3/include/seqan3/range/view/take_line.hpp:46, from test.cpp:1: /home/mi/h4nn3s/devel/seqan3/include/seqan3/core/metafunction/range.hpp:255:18: error: partial specialization ‘seqan3::dimension_v<t>’ does not specialize any template arguments and is not more constrained than the primary template; to define the primary template, remove the template argument list /home/mi/h4nn3s/devel/seqan3/include/seqan3/core/metafunction/range.hpp:246:18: note: primary template here