[3.6] bpo-30450: Improved logic for obtaining dependencies (#2751)

Adds alternate download approach for nuget.exe
Fall back to git.exe if no Python is found. (#2739)
Also check whether git.exe is on PATH if it will be used.
Add support for HOST_PYTHON variable.
Clear internal environment variables used in find_python.bat
Use HOST_PYTHON as the actual Python if it is recent enough.
Adds HOST_PYTHON variable to AppVeyor configuration

2 files changed, 4 insertions, 23 deletions

diff --git a/Tools/msi/buildrelease.bat b/Tools/msi/buildrelease.bat
index f60fe6a..1f52782 100644
--- a/Tools/msi/buildrelease.bat
+++ b/Tools/msi/buildrelease.bat
@@ -76,9 +76,6 @@ if ERRORLEVEL 1 (echo Cannot locate MSBuild.exe on PATH or as MSBUILD variable &
 if "%SKIPBUILD%" EQU "1" goto skipdoc
 if "%SKIPDOC%" EQU "1" goto skipdoc
 
-if not defined PYTHON where py -q || echo Cannot find py on path and PYTHON is not set. && exit /B 1
-if not defined SPHINXBUILD where sphinx-build -q || echo Cannot find sphinx-build on path and SPHINXBUILD is not set. && exit /B 1
-
 call "%D%..\..\doc\make.bat" htmlhelp
 if errorlevel 1 goto :eof
 :skipdoc
diff --git a/Tools/msi/get_externals.bat b/Tools/msi/get_externals.bat
index aece81f..913512a 100644
--- a/Tools/msi/get_externals.bat
+++ b/Tools/msi/get_externals.bat
@@ -12,7 +12,7 @@ set DO_FETCH=true
 set DO_CLEAN=false
 
 :CheckOpts
-if "%~1"=="--python" (set PYTHON_FOR_BUILD=%2) & shift & shift & goto CheckOpts
+if "%~1"=="--python" (set PYTHON=%2) & shift & shift & goto CheckOpts
 if "%~1"=="--organization" (set ORG=%2) & shift & shift & goto CheckOpts
 if "%~1"=="-c" (set DO_CLEAN=true) & shift & goto CheckOpts
 if "%~1"=="--clean" (set DO_CLEAN=true) & shift & goto CheckOpts
@@ -32,23 +32,7 @@ if "%DO_FETCH%"=="false" goto end
 
 if "%ORG%"=="" (set ORG=python)
 
-if "%PYTHON_FOR_BUILD%"=="" (
-    echo Checking for installed python...
-    py -3.6 -V >nul 2>&1 && (set PYTHON_FOR_BUILD=py -3.6)
-)
-if "%PYTHON_FOR_BUILD%"=="" (
-    if NOT exist "%EXTERNALS_DIR%" mkdir "%EXTERNALS_DIR%"
-    if NOT exist "%NUGET%" (
-        echo Downloading nuget...
-        rem NB: Must use single quotes around NUGET here, NOT double!
-        rem Otherwise, a space in the path would break things
-        powershell.exe -Command Invoke-WebRequest %NUGET_URL% -OutFile '%NUGET%'
-    )
-    echo Installing Python via nuget...
-    "%NUGET%" install pythonx86 -ExcludeVersion -OutputDirectory "%EXTERNALS_DIR%"
-    rem Quote it here; it's not quoted later because "py -3.6" wouldn't work
-    set PYTHON_FOR_BUILD="%EXTERNALS_DIR%\pythonx86\tools\python.exe"
-)
+call "%PCBUILD%\find_python.bat" "%PYTHON%"
 
 echo.Fetching external libraries...
 
@@ -59,7 +43,7 @@ for %%e in (%libraries%) do (
         echo.%%e already exists, skipping.
     ) else (
         echo.Fetching %%e...
-        %PYTHON_FOR_BUILD% "%PCBUILD%get_external.py" -e "%EXTERNALS_DIR%" -O %ORG% %%e
+        %PYTHON% "%PCBUILD%get_external.py" -e "%EXTERNALS_DIR%" -O %ORG% %%e
     )
 )
 
@@ -79,7 +63,7 @@ for %%b in (%binaries%) do (
         echo.%%b already exists, skipping.
     ) else (
         echo.Fetching %%b...
-        %PYTHON_FOR_BUILD% "%PCBUILD%get_external.py" -e "%EXTERNALS_DIR%" -b -O %ORG% %%b
+        %PYTHON% "%PCBUILD%get_external.py" -e "%EXTERNALS_DIR%" -b -O %ORG% %%b
     )
 )