I'm not sure what the problem is.
The command is:
root@root:/usr/lib/buildroot# make
And the error message is:
llvm 9.0.1 Building PATH="/usr/lib/buildroot/output/host/bin:/usr/lib/buildroot/output/host/sbin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games" /usr/bin/make -j3 -C /usr/lib/buildroot/output/build/llvm-9.0.1//buildroot-build make[1]: Entering directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' make[2]: Entering directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' make[3]: Entering directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' make[3]: Entering directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' make[3]: Entering directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' make[3]: Leaving directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' make[3]: Leaving directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' make[3]: Leaving directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' make[3]: Entering directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' make[3]: Entering directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' [ 0%] Building CXX object lib/TableGen/CMakeFiles/LLVMTableGen.dir/Error.cpp.o make[3]: Entering directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' [ 0%] Building CXX object lib/Demangle/CMakeFiles/LLVMDemangle.dir/Demangle.cpp.o aarch64-none-linux-gnu-g++: ERROR: unsafe header/library path used in cross-compilation: '-I/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build/lib/TableGen' lib/TableGen/CMakeFiles/LLVMTableGen.dir/build.make:62: recipe for target 'lib/TableGen/CMakeFiles/LLVMTableGen.dir/Error.cpp.o' failed make[3]: *** [lib/TableGen/CMakeFiles/LLVMTableGen.dir/Error.cpp.o] Error 1 make[3]: Leaving directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' CMakeFiles/Makefile2:879: recipe for target 'lib/TableGen/CMakeFiles/LLVMTableGen.dir/all' failed make[2]: *** [lib/TableGen/CMakeFiles/LLVMTableGen.dir/all] Error 2 make[2]: *** Waiting for unfinished jobs.... [ 0%] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/AArch64TargetParser.cpp.o [ 0%] Building CXX object lib/Demangle/CMakeFiles/LLVMDemangle.dir/ItaniumDemangle.cpp.o aarch64-none-linux-gnu-g++: ERROR: unsafe header/library path used in cross-compilation: '-I/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build/lib/Demangle' lib/Demangle/CMakeFiles/LLVMDemangle.dir/build.make:62: recipe for target 'lib/Demangle/CMakeFiles/LLVMDemangle.dir/Demangle.cpp.o' failed make[3]: *** [lib/Demangle/CMakeFiles/LLVMDemangle.dir/Demangle.cpp.o] Error 1 make[3]: *** Waiting for unfinished jobs.... aarch64-none-linux-gnu-g++: ERROR: unsafe header/library path used in cross-compilation: '-I/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build/lib/Support' lib/Support/CMakeFiles/LLVMSupport.dir/build.make:62: recipe for target 'lib/Support/CMakeFiles/LLVMSupport.dir/AArch64TargetParser.cpp.o' failed make[3]: *** [lib/Support/CMakeFiles/LLVMSupport.dir/AArch64TargetParser.cpp.o] Error 1 make[3]: *** Waiting for unfinished jobs.... aarch64-none-linux-gnu-g++: ERROR: unsafe header/library path used in cross-compilation: '-I/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build/lib/Demangle' lib/Demangle/CMakeFiles/LLVMDemangle.dir/build.make:75: recipe for target 'lib/Demangle/CMakeFiles/LLVMDemangle.dir/ItaniumDemangle.cpp.o' failed make[3]: *** [lib/Demangle/CMakeFiles/LLVMDemangle.dir/ItaniumDemangle.cpp.o] Error 1 make[3]: Leaving directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' CMakeFiles/Makefile2:640: recipe for target 'lib/Demangle/CMakeFiles/LLVMDemangle.dir/all' failed make[2]: *** [lib/Demangle/CMakeFiles/LLVMDemangle.dir/all] Error 2 [ 0%] Building CXX object lib/Support/CMakeFiles/LLVMSupport.dir/ARMTargetParser.cpp.o aarch64-none-linux-gnu-g++: ERROR: unsafe header/library path used in cross-compilation: '-I/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build/lib/Support' lib/Support/CMakeFiles/LLVMSupport.dir/build.make:75: recipe for target 'lib/Support/CMakeFiles/LLVMSupport.dir/ARMTargetParser.cpp.o' failed make[3]: *** [lib/Support/CMakeFiles/LLVMSupport.dir/ARMTargetParser.cpp.o] Error 1 make[3]: Leaving directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' CMakeFiles/Makefile2:800: recipe for target 'lib/Support/CMakeFiles/LLVMSupport.dir/all' failed make[2]: *** [lib/Support/CMakeFiles/LLVMSupport.dir/all] Error 2 make[2]: Leaving directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' Makefile:151: recipe for target 'all' failed make[1]: *** [all] Error 2 make[1]: Leaving directory '/usr/lib/buildroot/output/build/llvm-9.0.1/buildroot-build' package/pkg-generic.mk:266: recipe for target '/usr/lib/buildroot/output/build/llvm-9.0.1/.stamp_built' failed make: *** [/usr/lib/buildroot/output/build/llvm-9.0.1/.stamp_built] Error 2