Python 3.5 failing to install due to missing logfile

[dvorapa]

Pywikibot Python installation on AppVeyor fails with the following error:

mkdir appveyor
$wc = new-object net.webclient
$run = $wc.DownloadString($env:APPVEYOR_PYTHON_URL + 'run_with_env.cmd')
$run | Out-File -Encoding ascii -FilePath appveyor\run_with_env.cmd
if (-not(Test-Path($env:PYTHON))) {
  iex $wc.DownloadString($env:APPVEYOR_PYTHON_URL + 'install.ps1')
}
Installing Python 3.5.0 for 64 bit architecture to C:\Python350-x64
Downloading python-3.5.0-amd64.exe from https://www.python.org/ftp/python/3.5.0/python-3.5.0-amd64.exe
File saved at C:\projects\pywikibot\python-3.5.0-amd64.exe
Installing C:\projects\pywikibot\python-3.5.0-amd64.exe to C:\Python350-x64
C:\projects\pywikibot\python-3.5.0-amd64.exe /quiet InstallAllUsers=1 TargetDir=C:\Python350-x64
Handles  NPM(K)    PM(K)      WS(K)     CPU(s)     Id  SI ProcessName                                                                                                                                                                
-------  ------    -----      -----     ------     --  -- -----------                                                                                                                                                                
      3       2      276        640       0.00   1764   1 python-3.5.0-amd64                                                                                                                                                         
Failed to install Python in C:\Python350-x64
Get-Content : Cannot find path 'C:\Python350-x64.log' because it does not exist.
At line:128 char:9
+         Get-Content -Path $install_log
+         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (C:\Python350-x64.log:String) [Get-Content], ItemNotFoundException
    + FullyQualifiedErrorId : PathNotFound,Microsoft.PowerShell.Commands.GetContentCommand
 
Command exited with code