Does not seem to build with homebrew version of gfortran on OSX

With array fire installed to the default **/usr/local** directory, and this being correctly set in common.mk, this fails with the following error: **gfortran: error trying to exec 'cc1plus': execvp: No such file or directory**

When using gcc instead (changing @gfortran to gcc in the makefile), I get the following errors:

ndefined symbols for architecture x86_64:
"_MAIN__", referenced from:
_main in for_main.o
"__ZN2af14getDeviceCountEv", referenced from:
_af_device_count_ in fortran_wrapper.o
"__ZN2af15choleskyInPlaceERNS_5arrayEb", referenced from:
_af_arr_cholesky_inplace_ in fortran_wrapper.o
"__ZN2af2luERNS_5arrayES1_S1_RKS0_", referenced from:
_af_arr_lu_ in fortran_wrapper.o
"__ZN2af2qrERNS_5arrayES1_RKS0_", referenced from:
_af_arr_qr_ in fortran_wrapper.o
"__ZN2af3absERKNS_5arrayE", referenced from:
_af_arr_abs_ in fortran_wrapper.o
"__ZN2af3cosERKNS_5arrayE", referenced from:
_af_arr_cos_ in fortran_wrapper.o
"__ZN2af3expERKNS_5arrayE", referenced from:
_af_arr_exp_ in fortran_wrapper.o
"__ZN2af3logERKNS_5arrayE", referenced from:
_af_arr_log_ in fortran_wrapper.o
"__ZN2af3maxERKNS_5arrayEi", referenced from:
_af_arr_max_ in fortran_wrapper.o
"__ZN2af3minERKNS_5arrayEi", referenced from:
_af_arr_min_ in fortran_wrapper.o
"__ZN2af3powERKNS_5arrayES2_", referenced from:
_af_arr_elpow_ in fortran_wrapper.o
"__ZN2af3powERKNS_5arrayEd", referenced from:
_af_arr_scpow_ in fortran_wrapper.o
"__ZN2af3seqC1Eddd", referenced from:
_af_arr_get_ in fortran_wrapper.o
_af_arr_get2_ in fortran_wrapper.o
_af_arr_get_seq_ in fortran_wrapper.o
_af_arr_set_ in fortran_wrapper.o
_af_arr_set2_ in fortran_wrapper.o
_af_arr_set_seq_ in fortran_wrapper.o
_af_idx_seq_ in fortran_wrapper.o

先从 common.mk 和 makefile 开始，然后使用默认的 /usr/local 安装，在 macOS 上复现 Homebrew gfortran 构建。检查 cc1plus 失败以及报告的未定义符号；当 Fortran wrapper 使用文档中说明的配置成功构建并链接时，即表示完成。

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