We use mainly the "llvm" coding style, with some minor deviations. See .clang-format and .clang-tidy for the details.
Libraries that are not so common in the Ubuntu repositories are imported as source code
by means of
Git Submodules.
This is not without problems.
See also: Why do am i getting error 404 on my sub module symlink found on my git repo?
in [project root]/lib/spdlog do:
$ git fetch origin
$ git reset --hard v1.8.1
see also Git submodules best practices