I am also seeing the warnings (mentioned below) out of GCC:
Using built-in specs.
COLLECT_GCC=/usr/bin/g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/powerpc64le-linux-gnu/9/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: powerpc64le-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 9.3.0-17ubuntu1~20.04' --with-bugurl=file:///usr/share/doc/gcc-9/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,gm2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-9 --program-prefix=powerpc64le-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --enable-plugin --enable-default-pie --with-system-zlib --disable-libphobos --enable-objc-gc=auto --enable-secureplt --with-cpu=power8 --enable-targets=powerpcle-linux --disable-multilib --enable-multiarch --disable-werror --with-long-double-128 --enable-offload-targets=nvptx-none=/build/gcc-9-xsOZPb/gcc-9-9.3.0/debian/tmp-nvptx/usr --without-cuda-driver --enable-checking=release --build=powerpc64le-linux-gnu --host=powerpc64le-linux-gnu --target=powerpc64le-linux-gnu
Thread model: posix
gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)