Use the newest version of fmt may occurr error

[ghost]

It may occurr errors about fmt when I use the newest version of fmt (8.1.1) to build project.
Errors as following (a part):

...
/usr/local/include/fmt/core.h:1699:3: error: static assertion failed: Cannot format an argument. To make type T formattable provide a formatter<T> specialization: https://fmt.dev/latest/api.html#udt
   static_assert(
...
/usr/local/include/fmt/core.h:1699:3: error: static assertion failed: Cannot format an argument. To make type T formattable provide a formatter<T> specialization: https://fmt.dev/latest/api.html#udt
...
/usr/local/include/fmt/format.h:1068:4: error: use of ‘fmt::v8::detail::count_digits(UInt)::<lambda(UInt)> [with int BITS = 4; UInt = unsigned int]’ before deduction of ‘auto’
   return [](UInt m) {
          ~~~~~~~~~~~~
     int num_digits = 0;
     ~~~~~~~~~~~~~~~~~~~
     do {
     ~~~~
       ++num_digits;
       ~~~~~~~~~~~~~
     } while ((m >>= BITS) != 0);
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     return num_digits;
     ~~~~~~~~~~~~~~~~~~
   }(n);
...
/usr/local/include/fmt/format.h:1068:4: error: use of ‘fmt::v8::detail::count_digits(UInt)::<lambda(UInt)> [with int BITS = 1; UInt = unsigned int]’ before deduction of ‘auto’
...
/usr/local/include/fmt/format.h:1068:4: error: use of ‘fmt::v8::detail::count_digits(UInt)::<lambda(UInt)> [with int BITS = 3; UInt = unsigned int]’ before deduction of ‘auto’
...
/usr/local/include/fmt/format.h:1068:4: error: use of ‘fmt::v8::detail::count_digits(UInt)::<lambda(UInt)> [with int BITS = 4; UInt = long unsigned int]’ before deduction of ‘auto’
...

You might get other errors about fmt.
Try use old version of fmt to rebuild Sophus, I built successful with fmt 8.0.0.
OS: Ubuntu 18.04.6 LTS
Compiler: g++

[NikolausDemmel]

So what's the error? Which OS and compiler?

[cwg968]

i absolutely agree with you, because i recently met the same situation. @Jiajie-Shi

[NikolausDemmel]

Sophus compiles fine on macOS with AppleClang with fmt 8.1.1, so it might be an issue related to older GCC. I suggest checking which GCC version is affected and maybe trying to come up with a minimal reproducible example to possibly raise this issue over at libfmt.

[YonatanSimson]

OS: Ubuntu 18.04.6 LTS
Installing fmt package solved the issue for me:
sudo apt-get install -y libfmt-dev