title: Pipx failed to build packages
body: <p>When I run the command pipx install eth-brownie I receive the following error message,</p>
  <pre><code>fatal error from pip prevented installation. Full pip output in file:
      /Users/gentgjonbalaj/.local/pipx/logs/cmd_2021-10-22_11.10.14_pip_errors.log
  
  pip failed to build package:
      cytoolz
  
  Some possibly relevant errors from pip install:
      cytoolz/functoolz.c:23087:19: error: implicit declaration of function '_PyGen_Send' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
      cytoolz/functoolz.c:23092:19: error: implicit declaration of function '_PyGen_Send' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
      cytoolz/functoolz.c:23176:19: error: implicit declaration of function '_PyGen_Send' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
      error: command '/usr/bin/clang' failed with exit code 1
  
  Error installing eth-brownie.
  </code></pre>
  <p>I tried to use the command &quot;pip install eth-brownie&quot; but my terminal says &quot;pip command not found.&quot;</p>