title: Packaged build environment as build_requires of profiles, system compiler is used instead
body: <p>I will try to describe my setup first:</p>
  <ul>
  <li>conan 1.29.2</li>
  <li>Official <code>cmake/3.18.2</code> package</li>
  <li>Custom <code>gcc</code> package with <strong><code>package_info</code> including its bin directory in <code>PATH</code> and setting the <code>CC</code> and <code>CXX</code> env variables</strong>:
  <pre class="lang-py prettyprint-override"><code>def package(self):
      autotools = AutoToolsBuildEnvironment(self)
      autotools.make(target='install-strip')
  
  def package_info(self):
      bin_folder = os.path.join(self.package_folder, 'bin')
  
      self.env_info.path.append(bin_folder)
      self.env_info.CXX = os.path.join(bin_folder, 'g++')
      self.env_info.CC = os.path.join(bin_folder, 'gcc')
  </code></pre>
  </li>
  <li><code>linux-x86_64</code> conan profile representing Linux 64 bit environment as follows:
  <pre><code>[settings]
  os=Linux
  os_build=Linux
  arch=x86_64
  arch_build=x86_64
  </code></pre>
  </li>
  <li><code>linux-x86_64-Debug</code> conan profile representing Linux 64 bit Release environment as follows:
  <pre><code>include(linux-x86_64)
  
  [settings]
  build_type=Debug
  </code></pre>
  </li>
  <li><code>gcc-10.1.0</code> conan profile to build packages using my <code>gcc</code> package:
  <pre><code>[settings]
  compiler=gcc
  compiler.version=10.1
  compiler.libcxx=libstdc++11
  
  [build_requires]
  gcc/10.1.0
  </code></pre>
  </li>
  <li><code>cmake-3.18.2</code> conan profile to build packages using official <code>cmake</code> package:
  <pre><code>[build_requires]
  cmake/3.18.2
  </code></pre>
  </li>
  <li><code>default</code> conan profile with gcc 7</li>
  </ul>
  <p>If I try to build a package as follows:</p>
  <pre class="lang-sh prettyprint-override"><code>$ conan create . foo/version --build=missing -pr linux-x86_64-Debug -pr cmake-3.18.2 -pr gcc-10.1.0
  </code></pre>
  <p>the resulting config is:</p>
  <pre><code>Configuration:
  [settings]
  arch=x86_64
  arch_build=x86_64
  build_type=Debug
  compiler=gcc
  compiler.libcxx=libstdc++11
  compiler.version=10.1
  os=Linux
  os_build=Linux
  [options]
  [build_requires]
  *: gcc/10.1.0, cmake/3.18.2
  [env]
  </code></pre>
  <p><em>which looks right to me...</em></p>
  <p>and then conan starts building <code>cmake</code> package for the gcc 10.1 x86_64 config:</p>
  <pre><code>cmake/3.18.2: WARN: Build folder is dirty, removing it: /home/manuel/.conan/data/cmake/3.18.2/_/_/build/46c0026dddc0e0537a797652343e8e1e9d0e39e7
  cmake/3.18.2: Copying sources to build folder
  cmake/3.18.2: Building your package in /home/manuel/.conan/data/cmake/3.18.2/_/_/build/46c0026dddc0e0537a797652343e8e1e9d0e39e7
  cmake/3.18.2: Generator cmake created conanbuildinfo.cmake
  cmake/3.18.2: Calling build()
  </code></pre>
  <p>But then build fails because the <code>cmake</code> package cmake config <strong>is using the system compiler</strong>:</p>
  <pre><code>-- The C compiler identification is GNU 7.4.0
  -- The CXX compiler identification is GNU 7.4.0
  -- Detecting C compiler ABI info
  -- Detecting C compiler ABI info - done
  -- Check for working C compiler: /usr/bin/cc - skipped
  -- Detecting C compile features
  -- Detecting C compile features - done
  -- Detecting CXX compiler ABI info
  -- Detecting CXX compiler ABI info - done
  -- Check for working CXX compiler: /usr/bin/c++ - skipped
  -- Detecting CXX compile features
  -- Detecting CXX compile features - done
  -- Conan: called by CMake conan helper
  -- Conan: called inside local cache
  -- Conan: Adjusting output directories
  -- Conan: Using cmake global configuration
  -- Conan: Adjusting default RPATHs Conan policies
  -- Conan: Adjusting language standard
  -- Conan: Compiler GCC&gt;=5, checking major version 10.1
  -- Conan: Checking correct version: 7.4
  CMake Error at ../conanbuildinfo.cmake:510 (message):
    Detected a mismatch for the compiler version between your conan profile
    settings and CMake:
  
    Compiler version specified in your conan profile: 10.1
  
    Compiler version detected in CMake: 7.4
  
    Please check your conan profile settings (conan profile show
    [default|your_profile_name])
  
    P.S.  You may set CONAN_DISABLE_CHECK_COMPILER CMake variable in order to
    disable this check.
  Call Stack (most recent call first):
    ../conanbuildinfo.cmake:592 (conan_error_compiler_version)
    ../conanbuildinfo.cmake:695 (check_compiler_version)
    ../conanbuildinfo.cmake:249 (conan_check_compiler)
    CMakeLists.txt:9 (conan_basic_setup)
  </code></pre>
  <p>This looks very similar to <a href="https://github.com/conan-io/conan/issues/1842" rel="nofollow noreferrer">https://github.com/conan-io/conan/issues/1842</a>, but that issue is from 3 years ago.</p>