--- UPDATE ---

I now have :

• gcc (GCC) 7.1.0 (built from sources)

With it and cmake3 I can now try to build Clangd but I get an error during the make -j 8.

Details of the error can be found in this comment but the takeaway is :

[  6%] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/Process.cpp.o
	In file included from /home/kavan/Downloads/llvm-project/llvm/lib/Support/Process.cpp:107:0:
	/home/kavan/Downloads/llvm-project/llvm/lib/Support/Unix/Process.inc: Dans la fonction membre statique « static std::error_code llvm::sys::Process::FixupStandardFileDescriptors() »:
	/home/kavan/Downloads/llvm-project/llvm/lib/Support/Unix/Process.inc:209:54: error: initialisation invalide pour une référence du type « int (&)(int, stat*) noexcept » à partir d'une expression de type « int(int, stat*) noexcept »
	     if (RetryAfterSignal(-1, ::fstat, StandardFD, &st) < 0) {
		                                              ^
	In file included from /home/kavan/Downloads/llvm-project/llvm/lib/Support/Unix/Unix.h:23:0,
		         from /home/kavan/Downloads/llvm-project/llvm/lib/Support/Unix/Process.inc:13,
		         from /home/kavan/Downloads/llvm-project/llvm/lib/Support/Process.cpp:107:
	/home/kavan/Downloads/llvm-project/llvm/include/llvm/Support/Errno.h:32:23: note: dans le passage de l'argument 2 de « decltype(auto) llvm::sys::RetryAfterSignal(const FailT&, const Fun&, const Args& ...) [avec FailT = int; Fun = int(int, stat*) noexcept; Args = {int, stat*}] »
	 inline decltype(auto) RetryAfterSignal(const FailT &Fail, const Fun &F,
		               ^~~~~~~~~~~~~~~~
	make[2]: *** [lib/Support/CMakeFiles/LLVMSupport.dir/Process.cpp.o] Erreur 1
	make[1]: *** [lib/Support/CMakeFiles/LLVMSupport.dir/all] Erreur 2
	make: *** [all] Erreur 2

Any help is welcome.

--- END UPDATE ---

CentOS 7 is required for my work, usually I use Neovim with Clangd to develop.

Here are the version of some programs that could be of use :

• gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-44)

• GNU Make 3.82

• cmake3 version 3.17.5

• cmake version 2.8.12.2

• clang version 3.4.2 (tags/RELEASE_34/dot2-final)

Clangd isn't in the yum repos (although clang version 3.4.2 is).

I tried installing clangd via snap, but clangd --version just never gives the prompt back without printing anything (Ctrl-C needed to get the prompt back).

I tried building it from source, but gcc isn't recent enough :

CMake Error at cmake/modules/CheckCompilerVersion.cmake:37 (message):
  Host GCC version must be at least 7.1, your version is 4.8.5.

Has anyone been in this situation before ?