code: def check_requirements():
      
      if not os.path.exists(REQUIREMENTS):
          sys.exit(
              ansi.error() + ' %s is missing. Please check it in.' % ansi.underline(REQUIREMENTS)
          )
  
      with open(REQUIREMENTS, 'r', encoding='utf-8') as f:
          dependencies = f.readlines()
  
      vcs = [d for d in dependencies if re.match(r'^(-e )?(git|svn|hg|bzr).*', d)]
  
      dependencies = list(set(dependencies) - set(vcs))
  
      missing = []
      try:
          pkg_resources.require(dependencies)
      except (
          pkg_resources.ContextualVersionConflict,
          pkg_resources.DistributionNotFound,
          pkg_resources.VersionConflict
      ) as error:
          missing.append(str(error))
      except pkg_resources.RequirementParseError:
          pass
  
      if missing:
          missing = ' missing requirement:\n  ' + os.linesep.join(missing)
          if '--env-checked' in sys.argv:
              sys.exit(ansi.error() + missing + '\nRequirement installation failure, please check for errors in:\n $ lore install\n')
          else:
              print(ansi.warning() + missing)
              import lore.__main__
              lore.__main__.install_requirements(None)
              reboot('--env-checked')
docs: Make sure all listed packages from requirements.txt have been installed into the virtualenv at boot.