Regression in fmt 10+ with gcc: error: 'current_zone' is not a member of 'std::chrono'

[barracuda156]

Example of the issue: complexlogic/rsgain#126

The same code builds fine against libfmt 9, but fails with 10 and 11. Identical compiler is being used, gcc 14.2.0.

Log:

make[2]: Leaving directory `/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/build'
/usr/bin/make  -f src/CMakeFiles/rsgain.dir/build.make src/CMakeFiles/rsgain.dir/build
make[2]: Entering directory `/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/build'
[ 16%] Building CXX object src/CMakeFiles/rsgain.dir/easymode.cpp.o
cd /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/build/src && /opt/local/bin/ccache /opt/local/bin/g++-mp-14 -DBUILD_DATE=\"2024-09-12\" -I/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/build -isystem /opt/local/include -isystem /opt/local/include/taglib -isystem /opt/local/include/libfmt11 -pipe -Os -DNDEBUG -I/opt/local/include -D_GLIBCXX_USE_CXX11_ABI=0 -std=gnu++20 -arch ppc -mmacosx-version-min=10.6 -MD -MT src/CMakeFiles/rsgain.dir/easymode.cpp.o -MF CMakeFiles/rsgain.dir/easymode.cpp.o.d -o CMakeFiles/rsgain.dir/easymode.cpp.o -c /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/rsgain-3.5.2/src/easymode.cpp
[ 33%] Building CXX object src/CMakeFiles/rsgain.dir/output.cpp.o
cd /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/build/src && /opt/local/bin/ccache /opt/local/bin/g++-mp-14 -DBUILD_DATE=\"2024-09-12\" -I/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/build -isystem /opt/local/include -isystem /opt/local/include/taglib -isystem /opt/local/include/libfmt11 -pipe -Os -DNDEBUG -I/opt/local/include -D_GLIBCXX_USE_CXX11_ABI=0 -std=gnu++20 -arch ppc -mmacosx-version-min=10.6 -MD -MT src/CMakeFiles/rsgain.dir/output.cpp.o -MF CMakeFiles/rsgain.dir/output.cpp.o.d -o CMakeFiles/rsgain.dir/output.cpp.o -c /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/rsgain-3.5.2/src/output.cpp
[ 50%] Building CXX object src/CMakeFiles/rsgain.dir/scan.cpp.o
cd /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/build/src && /opt/local/bin/ccache /opt/local/bin/g++-mp-14 -DBUILD_DATE=\"2024-09-12\" -I/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/build -isystem /opt/local/include -isystem /opt/local/include/taglib -isystem /opt/local/include/libfmt11 -pipe -Os -DNDEBUG -I/opt/local/include -D_GLIBCXX_USE_CXX11_ABI=0 -std=gnu++20 -arch ppc -mmacosx-version-min=10.6 -MD -MT src/CMakeFiles/rsgain.dir/scan.cpp.o -MF CMakeFiles/rsgain.dir/scan.cpp.o.d -o CMakeFiles/rsgain.dir/scan.cpp.o -c /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/rsgain-3.5.2/src/scan.cpp
[ 66%] Building CXX object src/CMakeFiles/rsgain.dir/rsgain.cpp.o
cd /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/build/src && /opt/local/bin/ccache /opt/local/bin/g++-mp-14 -DBUILD_DATE=\"2024-09-12\" -I/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/build -isystem /opt/local/include -isystem /opt/local/include/taglib -isystem /opt/local/include/libfmt11 -pipe -Os -DNDEBUG -I/opt/local/include -D_GLIBCXX_USE_CXX11_ABI=0 -std=gnu++20 -arch ppc -mmacosx-version-min=10.6 -MD -MT src/CMakeFiles/rsgain.dir/rsgain.cpp.o -MF CMakeFiles/rsgain.dir/rsgain.cpp.o.d -o CMakeFiles/rsgain.dir/rsgain.cpp.o -c /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/rsgain-3.5.2/src/rsgain.cpp
[ 83%] Building CXX object src/CMakeFiles/rsgain.dir/tag.cpp.o
cd /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/build/src && /opt/local/bin/ccache /opt/local/bin/g++-mp-14 -DBUILD_DATE=\"2024-09-12\" -I/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/build -isystem /opt/local/include -isystem /opt/local/include/taglib -isystem /opt/local/include/libfmt11 -pipe -Os -DNDEBUG -I/opt/local/include -D_GLIBCXX_USE_CXX11_ABI=0 -std=gnu++20 -arch ppc -mmacosx-version-min=10.6 -MD -MT src/CMakeFiles/rsgain.dir/tag.cpp.o -MF CMakeFiles/rsgain.dir/tag.cpp.o.d -o CMakeFiles/rsgain.dir/tag.cpp.o -c /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/rsgain-3.5.2/src/tag.cpp
In file included from /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/rsgain-3.5.2/src/output.hpp:66,
                 from /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/rsgain-3.5.2/src/output.cpp:51:
/opt/local/include/libfmt11/fmt/chrono.h: In function 'tm fmt::v11::localtime(std::chrono::local_time<_Duration>)':
/opt/local/include/libfmt11/fmt/chrono.h:559:38: error: 'current_zone' is not a member of 'std::chrono'
  559 |       detail::to_time_t(std::chrono::current_zone()->to_sys(time)));
      |                                      ^~~~~~~~~~~~
make[2]: *** [src/CMakeFiles/rsgain.dir/output.cpp.o] Error 1
make[2]: *** Waiting for unfinished jobs....
In file included from /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/rsgain-3.5.2/src/output.hpp:66,
                 from /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/rsgain-3.5.2/src/tag.cpp:65:
/opt/local/include/libfmt11/fmt/chrono.h: In function 'tm fmt::v11::localtime(std::chrono::local_time<_Duration>)':
/opt/local/include/libfmt11/fmt/chrono.h:559:38: error: 'current_zone' is not a member of 'std::chrono'
  559 |       detail::to_time_t(std::chrono::current_zone()->to_sys(time)));
      |                                      ^~~~~~~~~~~~
make[2]: *** [src/CMakeFiles/rsgain.dir/tag.cpp.o] Error 1
In file included from /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/rsgain-3.5.2/src/output.hpp:66,
                 from /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/rsgain-3.5.2/src/scan.cpp:55:
/opt/local/include/libfmt11/fmt/chrono.h: In function 'tm fmt::v11::localtime(std::chrono::local_time<_Duration>)':
/opt/local/include/libfmt11/fmt/chrono.h:559:38: error: 'current_zone' is not a member of 'std::chrono'
  559 |       detail::to_time_t(std::chrono::current_zone()->to_sys(time)));
      |                                      ^~~~~~~~~~~~
make[2]: *** [src/CMakeFiles/rsgain.dir/scan.cpp.o] Error 1
In file included from /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/rsgain-3.5.2/src/output.hpp:66,
                 from /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/rsgain-3.5.2/src/rsgain.cpp:58:
/opt/local/include/libfmt11/fmt/chrono.h: In function 'tm fmt::v11::localtime(std::chrono::local_time<_Duration>)':
/opt/local/include/libfmt11/fmt/chrono.h:559:38: error: 'current_zone' is not a member of 'std::chrono'
  559 |       detail::to_time_t(std::chrono::current_zone()->to_sys(time)));
      |                                      ^~~~~~~~~~~~
make[2]: *** [src/CMakeFiles/rsgain.dir/rsgain.cpp.o] Error 1
In file included from /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/rsgain-3.5.2/src/output.hpp:66,
                 from /opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/rsgain-3.5.2/src/easymode.cpp:26:
/opt/local/include/libfmt11/fmt/chrono.h: In function 'tm fmt::v11::localtime(std::chrono::local_time<_Duration>)':
/opt/local/include/libfmt11/fmt/chrono.h:559:38: error: 'current_zone' is not a member of 'std::chrono'
  559 |       detail::to_time_t(std::chrono::current_zone()->to_sys(time)));
      |                                      ^~~~~~~~~~~~
make[2]: *** [src/CMakeFiles/rsgain.dir/easymode.cpp.o] Error 1
make[2]: Leaving directory `/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/build'
make[1]: *** [src/CMakeFiles/rsgain.dir/all] Error 2
make[1]: Leaving directory `/opt/local/var/macports/build/_opt_PPCSnowLeopardPorts_audio_rsgain/rsgain/work/build'
make: *** [all] Error 2

[vitaut]

Repro: https://www.godbolt.org/z/x4c4cdbTq

[vitaut]

This looks like a bug in libstdc++: the feature test macro is defined to 201907 but they don't implement current_zone. We could implement a workaround but please report to libstdc++ maintainers.

[vitaut]

Worked around in 538d877.

[barracuda156]

@vitaut Thank you!

I can open an issue on GCC bugzilla, let’s see what upstream says.

[barracuda156]

I have opened a ticket: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116777

[jwakely]

This looks like a bug in libstdc++: the feature test macro is defined to 201907 but they don't implement current_zone. We could implement a workaround but please report to libstdc++ maintainers.

This is because OP is using -D_GLIBCXX_USE_CXX11_ABI=0 and time zones have never been supported for that configuration. The feature test macro should have depended on the use of the cxx11 ABI, which was fixed by gcc-mirror/gcc@f906b10 for trunk and gcc-mirror/gcc@c386665 for gcc-14

[jwakely]

And that's because macports selects the old ABI for old macOS versions:
https://github.com/macports/macports-base/blob/a0c99ad1bf6363b556517a9b0ad91def3a812064/src/port1.0/portconfigure.tcl#L107

[barracuda156]

And that's because macports selects the old ABI for old macOS versions: https://github.com/macports/macports-base/blob/a0c99ad1bf6363b556517a9b0ad91def3a812064/src/port1.0/portconfigure.tcl#L107

Yes, you are right. If it did not, ports which use C++11 or higher cannot be linked to dependencies which are built against Apple libstdc++.

[barracuda156]

@iains Iain, do we have some solution to this? libfmt added a local workaround, but the same problem will inevitably resurface elsewhere.

[jwakely]

Don't expect to use C++20 features on an OS from 2011 🤷

[barracuda156]

@jwakely With a very few exceptions even C++23 works fine on the OS from 2011 :)