The follow program fails to link on Arch Linux with clang++.
g++ links as expected.

I think this is somewhat similar to issue #2794.

// Enabling this allows the program to always link.
//#define FMT_HEADER_ONLY

#include <cstdio>
#include <ctime>
#include <locale>

#include <fmt/chrono.h>
#include <fmt/format.h>

int main()
{
    std::puts(fmt::format(std::locale(""), "{:L%c}", fmt::gmtime(std::time_t{})).c_str());
}

clang++ fmt-link-fail.cpp -lfmt

fmt-link-fail.cpp:(.text+0x41): undefined reference to `_ZN3fmt3v1210locale_refC1ISt6localeTnNSt9enable_ifIXneszsrT_7collateLi0EEiE4typeELi0EEERKS5_'

I'm reaching the limits of my linker understanding here.

Is this supposed to work?
If the ABI is not compatible can I somehow detect this and automatically define FMT_HEADER_ONLY ?