sudo apt-get install git cmake ninja-build /usr/bin/clang-12 /usr/bin/clang++-12 /usr/bin/lld /usr/bin/llvm-link /usr/bin/conan libaio-devel libaio /usr/bin/antlr3
  
  git clone https://github.com/ydb-platform/ydb
  mkdir ydb_build
  cd $_
  cmake -G Ninja -DCMAKE_BUILD_TYPE=Release -DCMAKE_TOOLCHAIN_FILE=../ydb/clang.toolchain ../ydb
  ninja

Сборка падает на линковке
  FAILED: ydb/library/yql/udfs/common/math/Math_merged.udfs.bc 
  cd /home/keremet/compile/ydb_build/ydb/library/yql/udfs/common/math && /usr/bin/llvm-link /home/keremet/compile/ydb_build/ydb/library/yql/udfs/common/math/math_ir.cpp.udfs.bc /home/keremet/compile/ydb_build/ydb/library/yql/udfs/common/math/lib/erfinv.cpp.udfs.bc -o /home/keremet/compile/ydb_build/ydb/library/yql/udfs/common/math/Math_merged.udfs.bc
  llvm-link: /home/keremet/compile/ydb_build/ydb/library/yql/udfs/common/math/math_ir.cpp.udfs.bc: error: Unknown attribute kind (70) (Producer: 'LLVM12.0.1' Reader: 'LLVM 11.0.1')
Причина в том, что компилятор - clang12, а версия линковщика - 11
  [keremet@sl10 ydb_build]$ rpm -qf /usr/bin/llvm-link
  llvm-common-util-11.0.1-alt3.noarch
  [keremet@sl10 ydb_build]$