title: `Cannot open include file: 'apr_perms_set.h'` when doing `pip install mod_wsgi`
body: <p>I am trying to roll out a production Django environment on Windows 10 with Apache 2.4.37 x64 <a href="https://www.apachehaus.com/cgi-bin/download.plx" rel="noreferrer">OpenSSL 1.1.1 VC14 from ApacheHaus</a>. However, when following <a href="https://stackoverflow.com/a/42307082/1915854">these instructions</a>, I'm getting the following error:</p>
  
  <pre><code>  C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.16.27023\bin\HostX86\x64\cl.exe /c /nologo /Ox /W3 /GL /DNDEBUG /MD -ID:/Servers/Web/Apache/Apache24/include -Ic:\programs\python37\include -Ic:\programs\python37\include "-IC:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.16.27023\ATLMFC\include" "-IC:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.16.27023\include" "-IC:\Program Files (x86)\Windows Kits\NETFXSDK\4.6.1\include\um" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\ucrt" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\shared" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\um" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\winrt" "-IC:\Program Files (x86)\Windows Kits\10\include\10.0.17763.0\cppwinrt" /Tcsrc/server\mod_wsgi.c /Fobuild\temp.win-amd64-3.7\Release\src/server\mod_wsgi.obj
    mod_wsgi.c
    d:\servers\web\apache\apache24\include\apr_network_io.h(29): fatal error C1083: Cannot open include file: 'apr_perms_set.h': No such file or directory
    error: command 'C:\\Program Files (x86)\\Microsoft Visual Studio\\2017\\Community\\VC\\Tools\\MSVC\\14.16.27023\\bin\\HostX86\\x64\\cl.exe' failed with exit status 2
  
    ----------------------------------------
    Failed building wheel for mod-wsgi
  </code></pre>
  
  <p>I see the following options to C/C++ compiler: <code>-ID:/Servers/Web/Apache/Apache24/include -Ic:\programs\python37\include</code> . So it seems include file <code>apr_perms_set.h</code> is missing from Apache or Python.</p>
  
  <p>How to fix this error with the correct versions of the include files? I'm afraid it's wrong to just take the latest version from a repository because it may not match what's Apache or mod-wsgi expect.</p>