doesn't build on ubuntu 18.04 LLVMgold.so missing

In fact sorry about posting here, but uWebSockets doesn't accept issues. preparations

# make new machine on cloud hetzner
mkdir uws
cd uws
git clone https://github.com/uNetworking/uWebSockets --recursive
apt install -y make clang libssl-dev
cd uWebSockets
make

output

clang -flto -O3 -c -IuSockets/src uSockets/src/*.c uSockets/src/eventing/*.c
clang++ -flto -O3 -c -std=c++17 -Isrc -IuSockets/src examples/HelloWorld.cpp
clang++ -flto -O3 -s *.o -o HelloWorld
/usr/bin/ld: /usr/lib/llvm-6.0/bin/../lib/LLVMgold.so: error loading plugin: /usr/lib/llvm-6.0/bin/../lib/LLVMgold.so: cannot open shared object file: No such file or directory
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Makefile:4: recipe for target 'examples' failed
make: *** [examples] Error 1

apt install -y llvm doesn't help

clang -v

clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
Found candidate GCC installation: /usr/bin/../lib/gcc/i686-linux-gnu/8
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/7.3.0
Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.3.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Selected GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/7.3.0
Candidate multilib: .;@m64
Selected multilib: .;@m64

uNetworking / uSockets

doesn't build on ubuntu 18.04 LLVMgold.so missing #16