gmake clean
gmake -j2 INST_TOP=C:\perl CCHOME="c:\Program Files\mingw-w64\x86_64-8.1.0-posix-seh-rt_v6-rev0\mingw64" INST_ARCH=\x64
gmake install

c:\perl\bin\x64\perl -V
Can't locate Config.pm in @INC (you may need to install the Config module) (@INC contains:).
BEGIN failed--compilation aborted.