[snip]
/home/user/opt/pawn/pawn/pci.cc: In static member function ‘static absl::StatusOr<security::pawn::Pci> security::pawn::Pci::Create()’:
/home/user/opt/pawn/pawn/pci.cc:53:10: error: could not convert ‘pci’ from ‘security::pawn::Pci’ to ‘absl::StatusOr<security::pawn::Pci>’
   return pci;
          ^~~
/home/user/opt/pawn/pawn/physical_memory.cc: In static member function ‘static absl::StatusOr<std::unique_ptr<security::pawn::PhysicalMemory> > security::pawn::PhysicalMemory::Create(uintptr_t, size_t)’:
/home/user/opt/pawn/pawn/physical_memory.cc:45:10: error: could not convert ‘mem’ from ‘std::unique_ptr<security::pawn::PhysicalMemory>’ to ‘absl::StatusOr<std::unique_ptr<security::pawn::PhysicalMemory> >’
   return mem;

[snip]

$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 7.5.0-3ubuntu1~18.04' --with-bugurl=file:///usr/share/doc/gcc-7/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr --with-gcc-major-version-only --program-suffix=-7 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie --with-system-zlib --with-target-system-zlib --enable-objc-gc=auto --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)