[Debichem-devel] Bug#769525: nwchem: FTBFS on arm64

[Edmund Grimley Evans]

Source: nwchem
Version: 6.5+r26243-3

It failed to build on arm64:

http://buildd.debian.org/status/package.php?p=nwchem&suite=sid

The error was:

gfortran -c -m64 -ffast-math  -Warray-bounds -fdefault-integer-8 -O2
-g -fno-aggressive-loop-optimizations  -I.
-I/«BUILDDIR»/nwchem-6.5+r26243/src/include
-I/«BUILDDIR»/nwchem-6.5+r26243/src/tools/install/include -DLINUX
-DGCC4 -DGCC46 -DGFORTRAN -DGFORTRAN -DCHKUNDFLW -DGCC4 -DGCC46
-DEXT_INT -DLINUX -DLINUX64 -DPARALLEL_DIAG   basis.F
gfortran: error: unrecognized command line option '-m64'

At line 1761 of src/config/makefile.h there is code to avoid setting
-m64 for arm64:

       ifeq ($(_CPU),aarch64)
         DONTHAVEM64OPT=Y
       endif

However, I don't think _CPU has been set at this point. A simple fix
is to add this (which also appears elsewhere in the file) immediately
before the test:

       _CPU = $(shell uname -m  )