title: Cannot force install GD with cpan/cpanm
body: <p>I have looked and seen similar issues posted but am unable to get GD working. the following error arises <strong>with libgd and libpng installed</strong>...</p>
  
  <pre><code>clang -c  -I/usr/local/include -arch i386 -arch x86_64 -g -pipe -fno-common -DPERL_DARWIN -fno-strict-aliasing -fstack-protector -I/usr/local/include -Wformat=0 -Os   -DVERSION=\"2.50\" -DXS_VERSION=\"2.50\"  "-I/System/Library/Perl/5.12/darwin-thread-multi-2level/CORE"  -DHAVE_FT -DHAVE_GIF -DHAVE_ANIMGIF -DVERSION_33 -DHAVE_UNCLOSEDPOLY -DHAVE_FTCIRCLE GD.c
  GD.xs:997:18: warning: implicit declaration of function 'gdImageGifAnimBeginPtr' is invalid in C99 [-Wimplicit-function-declaration]
          data = (void *) gdImageGifAnimBeginPtr(image,&amp;size,globalcm,loops);
                          ^
  GD.xs:1022:18: warning: implicit declaration of function 'gdImageGifAnimAddPtr' is invalid in C99 [-Wimplicit-function-declaration]
          data = (void *) gdImageGifAnimAddPtr(image,&amp;size,localcm,leftofs,topofs,delay,disposal,previm);
                          ^
  GD.xs:1041:18: warning: implicit declaration of function 'gdImageGifAnimEndPtr' is invalid in C99 [-Wimplicit-function-declaration]
          data = (void *) gdImageGifAnimEndPtr(&amp;size);
                          ^
  GD.xs:1598:3: warning: implicit declaration of function 'gdImageOpenPolygon' is invalid in C99 [-Wimplicit-function-declaration]
                  gdImageOpenPolygon(image,polyptr,length,color);
                  ^
  GD.xs:2192:16: warning: using the result of an assignment as a condition without parentheses [-Wparentheses]
              if (value = hv_fetch(hash,"linespacing",strlen("linespacing"),0)) {
                  ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  GD.xs:2192:16: note: place parentheses around the assignment to silence this warning
              if (value = hv_fetch(hash,"linespacing",strlen("linespacing"),0)) {
                        ^
                  (                                                           )
  </code></pre>
  
  <p>...</p>
  
  <pre><code>2 warnings generated.
  rm -f blib/arch/auto/GD/GD.bundle
  LD_RUN_PATH="/usr/lib:/usr/local/lib" clang -mmacosx-version-min=10.8  -arch i386 -arch x86_64 -bundle -undefined dynamic_lookup -L/usr/local/lib -fstack-protector GD.o  -o blib/arch/auto/GD/GD.bundle    \
         -L/usr/local/lib -lz -liconv -lgd    \
  
  ld: warning: ignoring file /usr/local/lib/libgd.dylib, file was built for x86_64 which is not the architecture being linked (i386): /usr/local/lib/libgd.dylib
  chmod 755 blib/arch/auto/GD/GD.bundle
  /usr/bin/perl -MExtUtils::Command::MM -e 'cp_nonempty' -- GD.bs blib/arch/auto/GD/GD.bs 644
  /usr/bin/perl "-Iblib/arch" "-Iblib/lib" bdf_scripts/bdf2gdfont.PLS bdf_scripts/bdf2gdfont.pl
  Extracting bdf2gdfont.pl (with variable substitutions)
  cp bdf_scripts/bdf2gdfont.pl blib/script/bdf2gdfont.pl
  /usr/bin/perl -MExtUtils::MY -e 'MY-&gt;fixin(shift)' -- blib/script/bdf2gdfont.pl
  Manifying blib/man1/bdf2gdfont.pl.1
  Manifying blib/man3/GD.3pm
  Manifying blib/man3/GD::Image.3pm
  Manifying blib/man3/GD::Polygon.3pm
  Manifying blib/man3/GD::Polyline.3pm
  Manifying blib/man3/GD::Simple.3pm
  Running Mkbootstrap for GD ()
  chmod 644 GD.bs
  PERL_DL_NONLAZY=1 /usr/bin/perl "-MExtUtils::Command::MM" "-MTest::Harness" "-e" "undef *Test::Harness::Switches; test_harness(0, 'blib/lib', 'blib/arch')" t/*.t
  Testing using gif support.
  t/GD.t ........ 
  Failed 6/12 subtests 
      (less 3 skipped subtests: 3 okay)
  t/Polyline.t .. ok
  
  Test Summary Report
  -------------------
  t/GD.t      (Wstat: 0 Tests: 12 Failed: 6)
    Failed tests:  2-7
  Files=2, Tests=13,  0 wallclock secs ( 0.02 usr  0.01 sys +  0.10 cusr  0.01 csys =  0.14 CPU)
  Result: FAIL
  Failed 1/2 test programs. 6/13 subtests failed.
  make: *** [test_dynamic] Error 255
  -&gt; FAIL Installing GD failed. See /Users/lraven/.cpanm/work/1391048234.74068/build.log for details. Retry with --force to force install it.
  Expiring 19 work directories.
  </code></pre>
  
  <p>All other modules I need are installing, just not GD.</p>
  
  <p>I am using OS X 10.8.5, bash version 3.2.48, perl version 5.012 and cpanm version 1.7 </p>