With libc++ 21 math/symengine fails to build, with errors similar to:
In file included from
/wrkdirs/usr/ports/math/symengine/work/symengine-0.14.0/cmake/checkcxx11.cpp:1:
In file included from /usr/include/c++/v1/unordered_map:589:
In file included from /usr/include/c++/v1/__algorithm/is_permutation.h:13:
In file included from /usr/include/c++/v1/__algorithm/comp.h:14:
In file included from /usr/include/c++/v1/__type_traits/is_integral.h:14:
/usr/include/c++/v1/__type_traits/remove_cv.h:22:32: error: unknown type
name '__remove_cv'; did you mean 'remove_cv'?
using type _LIBCPP_NODEBUG = __remove_cv(_Tp);
^
/usr/include/c++/v1/__type_traits/remove_cv.h:21:35: note: 'remove_cv'
declared here
struct _LIBCPP_NO_SPECIALIZATIONS remove_cv {
^
This is because libc++ 21 does not officially support clang < 19, and
even though I added quite a few patches to libc++ 21 to non-officially
support older gcc and clang versions, I never managed to make it support
clang 15 or gcc 12.
It seems that either removing the USES=llvm:min=15,max=15 fixes this
problem, as it then compiles with the default llvm 19. Alternatively,
the minimum version could be bumped to at least 16.
PR: 293246
Approved by: maintainer timeout (2 weeks)
MFH: 2026Q1
Dimitry Andric
8adee5d272