spdlog build issue

[cst-saswatm]

When I am trying to build the cloned repo. After all the compilations and exports its failing at specially building for spdlog. I am currently using an ubuntu version 16

**----->
cmake --build _builds --config Release
[ 80%] Built target spdlog
[ 90%] Building CXX object example/CMakeFiles/example.dir/example.cpp.o
/home/saswatm/RISC-V-TLM/spdlog/example/example.cpp:267:13: error: specialization of ‘template<class T, class Char, class Enable> struct fmt::v9::formatter’ in different namespace [-fpermissive]
struct fmt::formatter<my_type> : fmt::formatterstd::string
^
In file included from /home/saswatm/RISC-V-TLM/spdlog/include/spdlog/fmt/fmt.h:27:0,
from /home/saswatm/RISC-V-TLM/spdlog/include/spdlog/common.h:45,
from /home/saswatm/RISC-V-TLM/spdlog/include/spdlog/spdlog.h:12,
from /home/saswatm/RISC-V-TLM/spdlog/example/example.cpp:29:
/home/saswatm/RISC-V-TLM/spdlog/include/spdlog/fmt/bundled/core.h:791:8: error: from definition of ‘template<class T, class Char, class Enable> struct fmt::v9::formatter’ [-fpermissive]
struct formatter {
^
example/CMakeFiles/example.dir/build.make:75: recipe for target 'example/CMakeFiles/example.dir/example.cpp.o' failed
make[2]: *** [example/CMakeFiles/example.dir/example.cpp.o] Error 1
CMakeFiles/Makefile2:125: recipe for target 'example/CMakeFiles/example.dir/all' failed
make[1]: *** [example/CMakeFiles/example.dir/all] Error 2
Makefile:155: recipe for target 'all' failed
make: *** [all] Error 2

**----->

Any suggestions how to solve it.

[AmeyaVS]

I tried the build on Ubuntu 16.04 LTS, and I was able to build(after trivial source changes), and run the example.

Can you share the build environment details?

• Compiler used and it's version.
• SystemC Version Used and Compilation flag used to build it.

[AmeyaVS]

After looking at the file and the line number from the error message.
It seems to be a trivial fix in the following file spdlog/example/example.cpp:

diff --git a/example/example.cpp b/example/example.cpp
index ccfdcf2..03bd27d 100644
--- a/example/example.cpp
+++ b/example/example.cpp
@@ -263,15 +263,16 @@ struct my_type
 };
 
 #ifndef SPDLOG_USE_STD_FORMAT // when using fmtlib
+namespace fmt {
 template<>
-struct fmt::formatter<my_type> : fmt::formatter<std::string>
+struct formatter<my_type> : formatter<std::string>
 {
     auto format(my_type my, format_context &ctx) -> decltype(ctx.out())
     {
         return format_to(ctx.out(), "[my_type i={}]", my.i);
     }
 };
-
+}
 #else // when using std::format
 template<>
 struct std::formatter<my_type> : std::formatter<std::string>

But I would recommend moving to a little bit modern GNU Linux System, where fixing old compiler limitations would come back to hit you at various places.

Note: Also, this project requires C++17 standard at a minimum. You will need to make additional changes in the sources to build it with GCC 5.5 that is default on Ubuntu 16.04 with only support C++11 and C++14 at a minimum.