Cross-compiling from Linux to Android requires -lrt for the host toolset.

tools/gyp/v8.gyp

Index: tools/gyp/v8.gyp
diff --git a/tools/gyp/v8.gyp b/tools/gyp/v8.gyp
index 384f451df77c30ede1b0bfea330dd82a257f9c50..708defed9bea6bfbd35f53b4c2722b619426d671 100644
--- a/tools/gyp/v8.gyp
+++ b/tools/gyp/v8.gyp
@@ -722,6 +722,15 @@
                   }],
                 ],
               }, {
+                'link_settings': {
+                  'target_conditions': [

[yurys, 2013/08/28 14:08:34]

Will it work on Mac OS X?

[Benedikt Meurer, 2013/08/28 14:10:08]

Yes, Mac OS X uses mach_absolute_time() instead of clock_gettime() and there's
no -lrt nor clock_gettime() in OS X, so we don't need to care about linking to
librt. Android itself has clock_gettime() in libc.

+                    ['_toolset=="host"', {
+                      'libraries': [
+                        '-lrt'
+                      ]
+                    }]
+                  ]
+                },
                 'sources': [
                   '../../src/platform-linux.cc'
                 ]