CMake Error at cmake/libfmt.cmake:45 (MESSAGE):

    system libfmt library is not found or unusable

#define FMT_STATIC_THOUSANDS_SEPARATOR ','

#define FMT_HEADER_ONLY 1

#include <fmt/format-inl.h>

#include <iostream>

int main() {

  fmt::format_args::format_arg arg=

    fmt::detail::make_arg<fmt::format_context>(42);

    std::cout << fmt::vformat("The answer is {}.",

                              fmt::format_args(&arg, 1));

}

<source>: In function 'int main()':

<source>:7:47: error: no matching function for call to 'make_arg<fmt::v10::format_context>(int)'

    7 |     fmt::detail::make_arg<fmt::format_context>(42);

      |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~

In file included from /opt/compiler-explorer/libs/fmt/trunk/include/fmt/format.h:49,

                 from /opt/compiler-explorer/libs/fmt/trunk/include/fmt/format-inl.h:25,

                 from <source>:3:

/opt/compiler-explorer/libs/fmt/trunk/include/fmt/core.h:1588:20: note: candidate: 'constexpr fmt::v10::basic_format_arg<Context> fmt::v10::detail::make_arg(T&) [with Context = fmt::v10::basic_format_context<fmt::v10::appender, char>; T = int]' (near match)

 1588 | FMT_CONSTEXPR auto make_arg(T& val) -> basic_format_arg<Context> {

      |                    ^~~~~~~~

/opt/compiler-explorer/libs/fmt/trunk/include/fmt/core.h:1588:20: note:   conversion of argument 1 would be ill-formed:

<source>:7:48: error: cannot bind non-const lvalue reference of type 'int&' to an rvalue of type 'int'

    7 |     fmt::detail::make_arg<fmt::format_context>(42);

      |                                                ^~

/opt/compiler-explorer/libs/fmt/trunk/include/fmt/core.h:1559:31: note: candidate: 'template<bool PACKED, class Context, class T, typename std::enable_if<PACKED, int>::type <anonymous> > constexpr fmt::v10::detail::value<Context> fmt::v10::detail::make_arg(T&)'

 1559 | FMT_CONSTEXPR FMT_INLINE auto make_arg(T& val) -> value<Context> {

      |                               ^~~~~~~~

/opt/compiler-explorer/libs/fmt/trunk/include/fmt/core.h:1559:31: note:   template argument deduction/substitution failed:

<source>:7:47: error: type/value mismatch at argument 1 in template parameter list for 'template<bool PACKED, class Context, class T, typename std::enable_if<PACKED, int>::type <anonymous> > constexpr fmt::v10::detail::value<Context> fmt::v10::detail::make_arg(T&)'

    7 |     fmt::detail::make_arg<fmt::format_context>(42);

      |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~

<source>:7:47: note:   expected a constant of type 'bool', got 'fmt::v10::format_context' {aka 'fmt::v10::basic_format_context<fmt::v10::appender, char>'}

/opt/compiler-explorer/libs/fmt/trunk/include/fmt/core.h:1596:27: note: candidate: 'template<bool PACKED, class Context, class T, typename std::enable_if<(! PACKED), int>::type <anonymous> > constexpr fmt::v10::basic_format_arg<Context> fmt::v10::detail::make_arg(T&)'

 1596 | FMT_CONSTEXPR inline auto make_arg(T& val) -> basic_format_arg<Context> {

      |                           ^~~~~~~~

/opt/compiler-explorer/libs/fmt/trunk/include/fmt/core.h:1596:27: note:   template argument deduction/substitution failed:

<source>:7:47: error: type/value mismatch at argument 1 in template parameter list for 'template<bool PACKED, class Context, class T, typename std::enable_if<(! PACKED), int>::type <anonymous> > constexpr fmt::v10::basic_format_arg<Context> fmt::v10::detail::make_arg(T&)'

    7 |     fmt::detail::make_arg<fmt::format_context>(42);

      |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~

<source>:7:47: note:   expected a constant of type 'bool', got 'fmt::v10::format_context' {aka 'fmt::v10::basic_format_context<fmt::v10::appender, char>'}

Compiler returned: 1