Segmentation fault when include "influxdb.hpp" and "string" at the same time with gcc option "-fmodules-ts"

[ChihHao-Su]

It's weird, I cannot figure out why.

Situation

• When with option "-fmodules-ts"
• • If include any one of "influxdb.hpp" and "string", the minimal code example will compile and run successfully.
• • If include "influxdb.hpp" and "string" at the same time, it will compile without error. when running, segmentation fault.
• When without option "-fmodules-ts"
• • No matter how they are included, the minimal code example will compile and run successfully.

Minimal code example

//main.cxx
#include <string>
#include "influxdb.hpp"

int main(){
  std::string a{"asdfasdf"};
}

$ g++ -Wall -Wextra -fmodules-ts -g main.cxx
$ ./a.out
[1]    60926 segmentation fault (core dumped)  ./a.out

# Run with GDB:
(gdb) r
Starting program: /home/chihhao-su/Proj/json_import_to_influxdb/a.out 

This GDB supports auto-downloading debuginfo from the following URLs:
https://debuginfod.fedoraproject.org/ 
Enable debuginfod for this session? (y or [n]) y
Debuginfod has been enabled.
To make this setting permanent, add 'set debuginfod enabled on' to .gdbinit.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_Alloc_hider::_Alloc_hider (this=0x7ffff7b27e22 <_int_malloc+3682>, __dat=0x7ffff7b27e32 <_int_malloc+3698> "\377H\215\rf\334\025", __a=...) at /usr/src/debug/gcc-11.3.1-2.fc35.x86_64/obj-x86_64-redhat-linux/x86_64-redhat-linux/libstdc++-v3/include/ext/new_allocator.h:82
82	      new_allocator(const new_allocator&) _GLIBCXX_USE_NOEXCEPT { }
(gdb) bt
#0  std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_Alloc_hider::_Alloc_hider (this=0x7ffff7b27e22 <_int_malloc+3682>, 
    __dat=0x7ffff7b27e32 <_int_malloc+3698> "\377H\215\rf\334\025", __a=...)
    at /usr/src/debug/gcc-11.3.1-2.fc35.x86_64/obj-x86_64-redhat-linux/x86_64-redhat-linux/libstdc++-v3/include/ext/new_allocator.h:82
#1  0x000000000040150a in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string<std::allocator<char> > (
    this=0x7fffffffddf0, __s=0x40203a "asdfasdf", __a=...)
    at /usr/include/c++/11/bits/basic_string.h:534
#2  0x0000000000401280 in main () at main.cxx:6
(gdb) 

---

I suspected it might be some limitations(or bugs) in GCC which doesn't allow users to include a c++ header(e.g. use a header-only-third-party library) that uses the header-file-version of c++ standard library when enable option "-fmodules-ts". But I wrote a simple .hpp file including a class, which uses std::string that in header-file-version of c++ standard library:

#include <string>
namespace Foo
{
class Bar
{
private:
    std::string bar;
public:
    Bar(std::string foo): bar(foo) { }
};
};

And I try to include both of it and "string" in main.cxx, it can still compile and run sucessfully. I'm wondering if it's some thing with influxdb-cpp.