title: failed updating 58 targets when trying to build boost, what happened?
body: <p>build with command<br>
  <code>[mirror@hugemeow boost_1_51_0]$ ./b2 --prefix=$HOME/ins/ins-boost2</code> </p>
  
  <p>and failed with the following message, why?</p>
  
  <pre><code>common.copy stage/lib/libboost_timer.a
  common.mkdir bin.v2/libs/wave/build/gcc-4.1.2/release/link-static
  common.mkdir bin.v2/libs/wave/build/gcc-4.1.2/release/link-static/threading-multi
  gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.1.2/release/link-static/threading-multi/instantiate_cpp_exprgrammar.o
  gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.1.2/release/link-static/threading-multi/instantiate_cpp_grammar.o
  gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.1.2/release/link-static/threading-multi/instantiate_cpp_literalgrs.o
  gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.1.2/release/link-static/threading-multi/instantiate_defined_grammar.o
  gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.1.2/release/link-static/threading-multi/instantiate_predef_macros.o
  gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.1.2/release/link-static/threading-multi/instantiate_re2c_lexer.o
  gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.1.2/release/link-static/threading-multi/instantiate_re2c_lexer_str.o
  gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.1.2/release/link-static/threading-multi/token_ids.o
  gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.1.2/release/link-static/threading-multi/wave_config_constant.o
  common.mkdir bin.v2/libs/wave/build/gcc-4.1.2/release/link-static/threading-multi/cpplexer
  common.mkdir bin.v2/libs/wave/build/gcc-4.1.2/release/link-static/threading-multi/cpplexer/re2clex
  gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.1.2/release/link-static/threading-multi/cpplexer/re2clex/aq.o
  gcc.compile.c++ bin.v2/libs/wave/build/gcc-4.1.2/release/link-static/threading-multi/cpplexer/re2clex/cpp_re.o
  gcc.archive bin.v2/libs/wave/build/gcc-4.1.2/release/link-static/threading-multi/libboost_wave.a
  common.copy stage/lib/libboost_wave.a
  ...failed updating 58 targets...
  ...skipped 12 targets...
  ...updated 887 targets...
  [mirror@hugemeow boost_1_51_0]$ echo $?
  1
  </code></pre>
  
  <p>this issue is not the same as <a href="https://stackoverflow.com/questions/9230894/failed-to-build-boost">Failed to build boost</a> or <a href="https://stackoverflow.com/questions/5299468/unable-to-build-boost-libraries-with-gcc">Unable to build Boost libraries with GCC</a>, <strong>i following the instruction with link</strong> <a href="http://www.boost.org/doc/libs/1_51_0/more/getting_started/unix-variants.html" rel="nofollow noreferrer">http://www.boost.org/doc/libs/1_51_0/more/getting_started/unix-variants.html</a></p>