https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115797
--- Comment #6 from Sergei Trofimovich <slyfox at gcc dot gnu.org> --- Another build failure example is pipewire-1.2.0. There <math.h> is included indirectly through another <spa/utils/dll.h> header: https://gitlab.freedesktop.org/pipewire/pipewire/-/blob/master/spa/plugins/alsa/alsa-pcm.h#L23 FAILED: spa/tests/spa-include-test-spa_utils_dll_h.p/meson-generated_.._spa-include-test-spa_utils_dll_h.cpp.o g++ -Ispa/tests/spa-include-test-spa_utils_dll_h.p -Ispa/tests -I../spa/tests -Ispa/include -I../spa/include -I../spa/include-private -fdiagnostics-color=always -D_GLIBCXX_ASSERTIONS=1 -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wextra -Wpedantic -std=c++17 -fvisibility=hidden -fno-strict-aliasing -Werror=suggest-attribute=format -Wsign-compare -Wpointer-arith -Wformat -Wformat-security -Wimplicit-fallthrough -Wmissing-braces -Wtype-limits -Wvariadic-macros -Wmaybe-uninitialized -Wno-missing-field-initializers -Wno-unused-parameter -Wno-pedantic -Wdeprecated-declarations -Wunused-result -Werror=return-type -Werror=float-conversion -fPIE -MD -MQ spa/tests/spa-include-test-spa_utils_dll_h.p/meson-generated_.._spa-include-test-spa_utils_dll_h.cpp.o -MF spa/tests/spa-include-test-spa_utils_dll_h.p/meson-generated_.._spa-include-test-spa_utils_dll_h.cpp.o.d -o spa/tests/spa-include-test-spa_utils_dll_h.p/meson-generated_.._spa-include-test-spa_utils_dll_h.cpp.o -c spa/tests/spa-include-test-spa_utils_dll_h.cpp In file included from /<<NIX>>/gcc-15.0.0/include/c++/15.0.0/bits/cpp_type_traits.h:40, from /<<NIX>>/gcc-15.0.0/include/c++/15.0.0/cmath:44, from /<<NIX>>/gcc-15.0.0/include/c++/15.0.0/math.h:36, from ../spa/include/spa/utils/dll.h:13, from spa/tests/spa-include-test-spa_utils_dll_h.cpp:1: /<<NIX>>/gcc-15.0.0/include/c++/15.0.0/type_traits:69:3: error: template with C linkage 69 | template<typename _Tp> | ^~~~~~~~
