Problems when running "make update" in cmd.exe (Help needed)

Usually I’m reporting bugs on the bug tracker, but after relying on others to fix them for so long I decided to take matters into my own hands, as there are still over a dozen bugs that I reported still awaiting a fix.

So I am currently following the official guide to building Blender Building Blender/Windows - Blender Developer Wiki to try to build Blender for the first time.

I am using a brand new laptop for that so except for the 4 programs listed in the guide (Visual Studio with ‘Desktop Development with C++’ workload, SlikSvn, Git, CMake) the only other program I have installed is GitHub Desktop.

The first cloning step went smoothly without any problems but when coming to the step where make update is executed I get this message

Warning: Python not found, there is likely an issue with the library folder
No explicit msvc version requested, autodetecting version.

** Visual Studio 2022 Developer Command Prompt v17.3.4 ** Copyright (c) 2022 Microsoft Corporation

[vcvarsall.bat] Environment initialized for: ‘x64’ Compiler Detection successful, detected VS2022

The required external libraries in “C:\blender-git\blender…\lib\win64_vc15” are missing

Would you like to download them? (y/n)

I then inputted “y” and it started to download a lot of files (which I presume are libraries).

After some time time it stops at the file C:\blender-git\lib\win64_vc15 with the message:

Checked out revision 63037.
python not found, required for this operation

How should I react to this? As far as I know I don’t have anything Python related installed as the Building Blender/Windows - Blender Developer Wiki guide tells me to only install the ‘Desktop Development with C++’ workload and also doesn’t tell me to install anything else Python related.

By the way I know absolutely nothing about Python and what also surprises me is that apparently you can download Python Download Python | Python.org

Do I have to that? And if so what exactly would I be downloading, a Python compiler or IDE? I just can’t imagine how you would download a programming language, I mean like I can’t just download a C++ for example.

Thank you for helping me out!

Python is included in the svn libraries, not something you need to separately download, what happens when you run make update again?

Before running make update I ran make to see if it compiles at all.
To my surprise it did and when I opened blender.exe Blender seemed to work fine as far as I could tell.

After that I ran make update again and it said:

No explicit msvc version requested, autodetecting version.

** Visual Studio 2022 Developer Command Prompt v17.3.4 ** Copyright (c) 2022 Microsoft Corporation

[vcvarsall.bat] Environment initialized for: ‘x64’ Compiler Detection successful, detected VS2022

Updating Precompiled Libraries and Tests

And proceeds to download some files that where not downloaded the first time I ran make update.

After that I ran make and Blender compilers succesfully.

I presume that the files that were missed the first time I ran make update aren’t crucial to Blender?

After that I set up a new directory to try to build Blender from scratch again.

At the make update stage it said again that Python wasn’t found although I have downloaded it for the other Blender build.

This leaves me with three questions:

  1. Why didn’t CMake or whatever software performs make update find Python?
  2. If I download Python from Download Python | Python.org will CMake find it and if so would it clash with Python included in the svn libraries?
  3. You said: “Python is included in the svn libraries”. But I still don’t understand what exactly is included in the svn libraries. Is it a Python interpreter, IDE or what is it?
  1. probably a bug that only triggers the first time before it downloads the libs
  2. No it will ignore whatever you have locally installed, it only looks in the folder downloaded with SVN
  3. Blender requires python to run, so it’s a full python install, including interpreter, development headers and libraries so blender can run/link against them