Installing tools on MacOS fails

[shruthb]

I'm following UW CSEP451 course tools guide to install gdb but this is failing with the following message:

==> Installing i386-jos-elf-gcc from xiw/jos
==> Downloading https://ftpmirror.gnu.org/gcc/gcc-6.2.0/gcc-6.2.0.tar.bz2
Already downloaded: /Users/shruthb/Library/Caches/Homebrew/downloads/0259c746a5e848e0315aeffd87e4880ac9f9ac27cd9654277984f2a74d4d7f55--gcc-6.2.0.tar.bz2
==> ../configure --prefix=/usr/local/Cellar/i386-jos-elf-gcc/6.2.0 --enable-languages=c,go --disable-werror --disable-nls --disable-libssp --disable-libmudflap --disable-multilib --with-as=/usr/local/opt/i386-jo
==> make all-gcc
Last 15 lines from /Users/shruthb/Library/Logs/Homebrew/i386-jos-elf-gcc/02.make:
/usr/local/include/isl/mat.h:29:11: note: passing argument to parameter 'n_row' here
        unsigned n_row, unsigned n_col);
                 ^
11 errors generated.
make[1]: *** [graphite-isl-ast-to-gimple.o] Error 1
../../gcc/graphite-optimize-isl.c:59:19: error: use of undeclared identifier 'isl_space_dim'
  unsigned dims = isl_space_dim (space, isl_dim_set);
                  ^
../../gcc/graphite-optimize-isl.c:62:3: error: use of undeclared identifier 'isl_space_free'
  isl_space_free (space);
  ^
2 errors generated.
make[1]: *** [graphite-optimize-isl.o] Error 1
rm gcc.pod gccgo.pod
make: *** [all-gcc] Error 2

System details: macOS High Sierra (v10.13.6), Processor 3.1 GHz Intel Core i7