Report stl crash on `format` with `chrono::zoned_time`

[Sauterelle57]

Describe the bug

I encountered a crash while using std::chrono::zoned_time with std::format.
According to https://en.cppreference.com/w/cpp/chrono/zoned_time.html it's supposed to be supported, my program compiles correctly but crashes on format (see call stack below for more details).

Command-line test case

C:\Temp>type main.cpp
#include <iostream>
#include <chrono>
#include <string>
#include <format>
#include <iostream>

int main()
{
    using namespace std::chrono;

    auto now = floor<seconds>(system_clock::now());
    zoned_time local_zoned{ current_zone(), now };

    std::string ts = std::format("{:%Y%m%d_%H%M%S}", local_zoned);
    std::cout << std::format("../logs/NEXO-{}.log", ts) << std::endl;
    return 0;
}

C:\Temp>cl /EHsc /W4 /WX /std:c++latest .\main.cpp
Microsoft (R) C/C++ Optimizing Compiler Version 19.41.34120 for x64
Copyright (C) Microsoft Corporation.  All rights reserved.

/std:c++latest is provided as a preview of language features from the latest C++
working draft, and we're eager to hear about bugs and suggestions for improvements.
However, note that these features are provided as-is without support, and subject
to changes or removal as the working draft evolves. See
https://go.microsoft.com/fwlink/?linkid=2045807 for details.

main.cpp
Microsoft (R) Incremental Linker Version 14.41.34120.0
Copyright (C) Microsoft Corporation.  All rights reserved.

/out:main.exe
main.obj

C:\Temp>start /wait .\main.exe
C:\Temp>echo %errorlevel%
-1073740791

Expected behavior

C:\Temp>main.exe
../logs/NEXO-20250626_222325.log
C:\Temp>start /wait .\main.exe
C:\Temp>echo %errorlevel%
0

STL version

• Option 1: Visual Studio version

  Microsoft Visual Studio Community 2022 (64-bit) - Current
  Version 17.11.3
  

Additional context

cl version

Microsoft (R) C/C++ Optimizing Compiler Version 19.41.34120 for x64
Copyright (C) Microsoft Corporation. All rights reserved.

Windows 11 version

Version 24H2 build 26100.4351

Computer

Laptop Gigabyte G6X 9KG-43FR854SH

Crash details

Unhandled exception at 0x00007FFDC63E85EA in bugStdFormat.exe: Microsoft C++ exception: std::system_error at memory location 0x00000080334FD5F0.

Call stack

 	KernelBase.dll!00007ffdc63e85ea()	Unknown
 	vcruntime140d.dll!00007ffce9219362()	Unknown
 	msvcp140d.dll!00007ffcc9150689()	Unknown
>	bugStdFormat.exe!std::chrono::_Make_unique_tzdb_info<&__std_tzdb_get_sys_info,char const *,unsigned __int64 const &,double>(const char * && <_Args_0>, const unsigned __int64 & <_Args_1>, double && <_Args_2>) Line 1737	C++
 	bugStdFormat.exe!std::chrono::time_zone::_Get_info<std::chrono::duration<__int64,std::ratio<1,1>>>(const std::chrono::duration<__int64,std::ratio<1,1>> & _Dur, __std_tzdb_sys_info_type _Type) Line 1820	C++
 	bugStdFormat.exe!std::chrono::time_zone::get_info<std::chrono::duration<__int64,std::ratio<1,1>>>(const std::chrono::time_point<std::chrono::system_clock,std::chrono::duration<__int64,std::ratio<1,1>>> & _Sys) Line 1764	C++
 	bugStdFormat.exe!std::chrono::zoned_time<std::chrono::duration<__int64,std::ratio<1,1>>,std::chrono::time_zone const *>::get_info() Line 2519	C++
 	bugStdFormat.exe!std::formatter<std::chrono::zoned_time<std::chrono::duration<__int64,std::ratio<1,1>>,std::chrono::time_zone const *>,char>::format<std::basic_format_context<std::back_insert_iterator<std::_Fmt_buffer<char>>,char>>(const std::chrono::zoned_time<std::chrono::duration<__int64,std::ratio<1,1>>,std::chrono::time_zone const *> & _Val, std::basic_format_context<std::back_insert_iterator<std::_Fmt_buffer<char>>,char> & _FormatCtx) Line 5950	C++
 	bugStdFormat.exe!std::basic_format_arg<std::basic_format_context<std::back_insert_iterator<std::_Fmt_buffer<char>>,char>>::handle::{ctor}::__l1::<lambda_3_>::operator()(std::basic_format_parse_context<char> & _Parse_ctx, std::basic_format_context<std::back_insert_iterator<std::_Fmt_buffer<char>>,char> & _Format_ctx, const void * _Ptr) Line 723	C++
 	bugStdFormat.exe!`std::basic_format_arg<std::basic_format_context<std::back_insert_iterator<std::_Fmt_buffer<char>>,char>>::handle::handle<std::chrono::zoned_time<std::chrono::duration<__int64,std::ratio<1,1>>,std::chrono::time_zone const *>>'::`1'::<lambda_3_>::<lambda_invoker_cdecl>(std::basic_format_parse_context<char> & _Parse_ctx, std::basic_format_context<std::back_insert_iterator<std::_Fmt_buffer<char>>,char> & _Format_ctx, const void * _Ptr) Line 725	C++
 	bugStdFormat.exe!std::basic_format_arg<std::basic_format_context<std::back_insert_iterator<std::_Fmt_buffer<char>>,char>>::handle::format(std::basic_format_parse_context<char> & _Parse_ctx, std::basic_format_context<std::back_insert_iterator<std::_Fmt_buffer<char>>,char> & _Format_ctx) Line 729	C++
 	bugStdFormat.exe!std::_Format_handler<char>::_On_format_specs(const unsigned __int64 _Id, const char * _First, const char * _Last) Line 3663	C++
 	bugStdFormat.exe!std::_Parse_replacement_field<char,std::_Format_handler<char> &>(const char * _First, const char * _Last, std::_Format_handler<char> & _Handler) Line 1493	C++
 	bugStdFormat.exe!std::_Parse_format_string<char,std::_Format_handler<char> &>(std::basic_string_view<char,std::char_traits<char>> _Format_str, std::_Format_handler<char> & _Handler) Line 1544	C++
 	bugStdFormat.exe!std::vformat_to<std::back_insert_iterator<std::string>>(std::back_insert_iterator<std::string> _Out, const std::basic_string_view<char,std::char_traits<char>> _Fmt, const std::basic_format_args<std::basic_format_context<std::back_insert_iterator<std::_Fmt_buffer<char>>,char>> _Args) Line 3778	C++
 	bugStdFormat.exe!std::vformat<0>(const std::basic_string_view<char,std::char_traits<char>> _Fmt, const std::basic_format_args<std::basic_format_context<std::back_insert_iterator<std::_Fmt_buffer<char>>,char>> _Args) Line 3855	C++
 	bugStdFormat.exe!std::format<std::chrono::zoned_time<std::chrono::duration<__int64,std::ratio<1,1>>,std::chrono::time_zone const *> &>(const std::basic_format_string<char,std::chrono::zoned_time<std::chrono::duration<__int64,std::ratio<1,1>>,std::chrono::time_zone const *> &> _Fmt, std::chrono::zoned_time<std::chrono::duration<__int64,std::ratio<1,1>>,std::chrono::time_zone const *> & <_Args_0>) Line 3885	C++
 	bugStdFormat.exe!main() Line 13	C++
 	[External Code]	

[cpplearner]

1. What is the system's time zone, as can be found in Settings > Time & language > Date & time?
2. What is the system's region format, as can be found in Settings -> Time & Language -> Region -> Region Format?

[Sauterelle57]

1. What is the system's time zone, as can be found in Settings > Time & language > Date & time?

2. What is the system's region format, as can be found in Settings -> Time & Language -> Region -> Region Format?

1. (UTC-05:00) Est (E.-U. and Canada)
2. Canada

[cpplearner]

Hmm, I can't seem to reproduce the issue. I set the respective settings to "UTC-05:00" and "English (Canada)", and the output is ../logs/NEXO-20250626_174741.log as expected.

[cpplearner]

This is an "Unhandled exception" of type std::system_error. So can you catch the exception and print e.what()?

[Sauterelle57]

This is an "Unhandled exception" of type std::system_error. So can you catch the exception and print e.what()?

My locals are in french so the original message is:
Il nÆy a pas de caractÞre correspondant au caractÞre Unicode dans la page de codes multi-octet cible.,
that can be understood by:
No mapping for the Unicode character exists in the target multi-byte code page

[cpplearner]

Thanks. This is #3158, which I fixed recently in #5558.

In this case, std::format calls time_zone::get_info to get the time zone abbreviation, the localized abbreviation for the fr locale is UTC−5, where − is U+2212 MINUS SIGN, not the ASCII hyphen-minus, and the system's code page cannot represent U+2212.

Workaround: call std::setlocale(LC_ALL, ".UTF-8") to make time_zone::get_info encode the time zone abbreviation in UTF-8.

[Sauterelle57]

Thank you very much.
I fixed it with:

auto local_time = local_zoned.get_local_time();
std::string ts = std::format("{:%Y%m%d_%H%M%S}", local_time);