make test returns errors

[gdwrd]

Hi @mattn, I using your library for my project.
When I try to run make test, task is falling on mruby-thread.
So I try to test only your lib with crean mruby and build config from test_build.rb file, and I again get error.

Build summary:

================================================
      Config Name: host
 Output Directory: build/host
         Binaries: mrbc, mrbtest
    Included Gems:
             mruby-sprintf - standard Kernel#sprintf method
             mruby-print - standard print/puts/p
             mruby-math - standard Math module
             mruby-time - standard Time class
             mruby-struct - standard Struct class
             mruby-compar-ext - Enumerable module extension
             mruby-enum-ext - Enumerable module extension
             mruby-fiber - Fiber class
             mruby-enumerator - Enumerator class
             mruby-string-ext - String class extension
             mruby-numeric-ext - Numeric class extension
             mruby-array-ext - Array class extension
             mruby-hash-ext - Hash class extension
             mruby-range-ext - Range class extension
             mruby-proc-ext - Proc class extension
             mruby-symbol-ext - Symbol class extension
             mruby-random - Random class
             mruby-object-ext - Object class extension
             mruby-objectspace - ObjectSpace class
             mruby-enum-lazy - Enumerator::Lazy class
             mruby-toplevel-ext - toplevel object (main) methods extension
             mruby-compiler - mruby compiler library
             mruby-bin-mirb - mirb command
               - Binaries: mirb
             mruby-error - extensional error handling
             mruby-bin-mruby - mruby command
               - Binaries: mruby
             mruby-bin-strip - irep dump debug section remover command
               - Binaries: mruby-strip
             mruby-kernel-ext - Kernel module extension
             mruby-class-ext - class/module extension
             mruby-thread
             mruby-bin-mrbc - mruby compiler executable
             mruby-test - mruby test
================================================

>>> Test host <<<
mrbtest - Embeddable Ruby Test

..............................................................................................?...................................................................................................................................................................................................................................................................?....................X.rake aborted!
Command Failed: ["build/host/bin/mrbtest"]
rakefile:123:in `block (2 levels) in <top (required)>'
make: *** [test] Error 1
mruby_build|master ⇒

and here is build config

MRuby::Build.new do |conf|
  MRBGEMS_ROOT = "/usr/local/mrblib"
  toolchain :clang
  conf.cc.defines += %w(ENABLE_READLINE)
  conf.cc.include_paths << %w(/usr/local/include)
  conf.linker.library_paths << %w(/usr/local/lib)
  conf.linker.libraries << ['pthread']
  conf.gembox 'default'
  conf.gem File.dirname(__FILE__)
  conf.enable_test
end

But in my build config I get the same errors.