title: Using conan to package multiple configurations of preexisting binaries
body: <p>I have a set of third-party binaries that I am trying to put into a conan package. The binaries are in folders for the build configuration: Linux32, Win32, Win64, Win32. </p>
  
  <p>I have been able to produce a conan package for the Win64 configuration using the following conanfile.py:</p>
  
  <pre><code>from conans import ConanFile
  
  class LibNameConan(ConanFile):
      name = "LibName"
      version = "1.1.1"
      settings = "os", "compiler", "build_type", "arch"
      description = "Package for LibName"
      url = "None"
      license = "None"
  
      def package(self):
          self.copy("*", dst="lib", src="lib")
          self.copy("*.c", dst="include", src="include", keep_path=False)
  
      def package_info(self):
          self.cpp_info.libs = self.collect_libs()
  </code></pre>
  
  <p>I run the following commands in powershell:</p>
  
  <pre><code>conan install
  mkdir pkg
  cd pkg
  conan package .. --build_folder=../
  cd ..
  conan export name/testing
  conan package_files libname/1.1.1@name/testing
  </code></pre>
  
  <p>For the Win64 this works as expected. When I repeat the steps with Win32 binaries I do not get a different hash for the package.</p>
  
  <p>I have tried running:</p>
  
  <pre><code>conan install -s arch=x86
  </code></pre>
  
  <p>However, this still results in the package having the same hash as the x86_64 configuration.</p>
  
  <p>How is the configuration supposed to be set for generating a package from preexisting binaries?</p>