-DLLVM_RUNTIME_TARGETS and the corresponding
-DRUNTIMES_$target_LLVM_ENABLE_RUNTIMES=compiler-rt does not create runtime build targets. You also have to specify
-DLLVM_ENABLE_RUNTIMES=compiler-rt. This is confusing and pretty hard to fix if you don’t already know the solution. Is there a reason for this?
cmake -GNinja -DRUNTIMES_i386-unknown-linux-gnu_LLVM_ENABLE_RUNTIMES=compiler-rt -DLLVM_RUNTIME_TARGETS=i386-unknown-linux-gnu -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS='clang' -DLLVM_ENABLE_LLD=ON ../../llvm doesn’t create runtimes targets.