How to set Environment Variable to force VS 2019 to use 64-bit tools?

Windows
1

I am getting the following info when compiling my Release version of a GUI App, with VS 2019:

1>LINK : the 32-bit linker (C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\bin\HostX86\x64\link.exe) failed to do memory mapped file I/O on `x64\Release\App\xxxx-apphost.iobj' and is going to restart linking with a 64-bit linker for better throughput
1>LINK : restarting link with 64-bit linker `C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\bin\HostX64\x64\link.exe'

It eventually links but this takes way longer.

I have read that you can force VS 2019 to use the 64-bit linker tools (they user 32-bit by default, even if you are building 64-bit projects) by setting an Environment Variable for PreferredToolArchitecture=x64.

I am a Mac User, so this is new to me.

I tried setting like this in System Properties > Advanced > Environment Variables >
by adding a new Variable PreferredToolArchitecture with a value of x64:

Screenshot 2023-12-22 102655
Screenshot 2023-12-22 102655883×489 8.48 KB

… but it appears to have no effect. You can see in the Task Manager it is still using the 32-bit tools:

Screenshot 2023-12-22 103219
Screenshot 2023-12-22 1032191164×616 33.7 KB

2

Why not update to the fully 64 bit Visual Studio 2022?

3

Good question. Because I’m comfortable with it and worried I’ll mess something up?

Can you install VS 2022 and still keep your VS 2019 installation intact and usable?

4

Well, VS 2019 gives you problems :slight_smile:

Yes, you can run both versions alongside

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