CROSS_F77_TRUE_VALUE=1 CROSS_F77_FALSE_VALUE=0 CROSS_F77_SIZEOF_INTEGER=4 ../configure --host=riscv64-linux-gnu --prefix=/tmp/riscv/mpich CC=riscv64-linux-gnu-gcc-9 CXX=riscv64-linux-gnu-g++-9 FC=riscv64-linux-gnu-gfortran-9 --with-device=ch4:ofi

This results in the following error, which I cannot interpret.

checking for size of Fortran type integer... 4
checking for size of Fortran type real... 0
checking for size of Fortran type double precision... 0
checking whether integer*1 is supported... yes
checking whether integer*2 is supported... yes
checking whether integer*4 is supported... yes
checking whether integer*8 is supported... yes
checking whether integer*16 is supported... yes
checking whether real*4 is supported... yes
checking whether real*8 is supported... yes
checking whether real*16 is supported... yes
configure: WARNING: Unable to determine size of a DOUBLE PRECISION type; using 8
checking for C type matching Fortran real... unavailable
checking for C type matching Fortran double... unavailable
configure: WARNING: Unable to determine size of a DOUBLE PRECISION type; using 8
checking for C type matching Fortran integer... int
checking for values of Fortran logicals... True is 1 and False is 0
configure: error: '' is empty

Thanks,

Jeff