Wix Installer is tries to download .Net 8 when already installed

[cornerbowlsoftware]

I have customers in STIGed environments where the installer is failing because Wix is trying to download .Net from an air gapped machine when it's already installed. I have run tests with air gapped machines and cannot reproduce the issue. While working with another customer on a corporate non-STIGed machine, I noticed the following lines:

[129C:2330][2024-09-04T10:31:11]i338: Acquiring package: Net8Redist, payload: Net8Redist, download from: https://download.visualstudio.microsoft.com/download/pr/3980ab0a-379f-44a0-9be6-eaf74c07a3b3/bd1cc6107ff3d8fe0104d30f01339b74/dotnet-runtime-8.0.7-win-x64.exe
[4A3C:5BA4][2024-09-04T10:31:12]i305: Verified acquired payload: Net8Redist at path: C:\ProgramData\Package Cache\.unverified\Net8Redist, moving to: C:\ProgramData\Package Cache\E016B47FF8F179F1EDF641CCA20130E04951509F0F69F564F290BFB0AD81D7DB\dotnet-runtime-8.0.7-win-x64.exe.

However just above the log files states:

[129C:5A20][2024-09-04T10:31:05]i052: Condition 'DOT_NET_VER >= v8.0.0' evaluates to true.
[129C:5A20][2024-09-04T10:31:05]i101: Detected package: Net8Redist, state: Present, cached: No, install registration state: (permanent), cache registration state: (permanent)

Why is the installer downloading files it doesn't need?

[cornerbowlsoftware]

My DetectCondition is:

DetectCondition="DOT_NET_VER >= v8.0.0"

Is this backwards? I reviewed my previous Wix3 installers and they always ignore the .Net installation when the detect condition result equals true.

[cornerbowlsoftware]

I customer sent screenshots in PDF format of the logs and I can verify Wix is trying to install .Net 8 over and over again.

[csdahlberg]

I saw something similar when using NetFx462RedistAsPrereq. Our installer was correctly detecting that a newer .NET Framework version was already installed, but was attempting to download the 4.6.2 installer solely to cache it locally (not to actually install it). Switching to NetFx462WebAsPrereq avoided the attempt to download the 4.6.2 installer when 4.6.2+ was already installed.

As a short-term, no-code-change-required workaround, I also found that manually copying the .NET Framework 4.6.2 installer to %folder_with_our_installer%\redist\ndp462-kb3151800-x86-x64-allos-enu.exe allowed NetFx462RedistAsPrereq to succeed without reaching out to the internet.

Might either of those help you?

[cornerbowlsoftware]

@csdahlberg I am using the following .wxs to detect .Net 8. Are you suggesting I set a parameter such as PrereqPackage="no"?

Here is my wxs:

<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs" xmlns:netfx="http://wixtoolset.org/schemas/v4/wxs/netfx">

    <Fragment>        
        <netfx:DotNetCoreSearch RuntimeType="desktop" Platform="x64" MajorVersion="8" Variable="DOT_NET_VER" />

        <PackageGroup Id="Net8DesktopRedist">
            <ExePackage 
				Id="Net8DesktopRedist" 
				DisplayName="Microsoft .NET 8.0 Desktop Runtime (v8.0.8)" 
				Cache="keep" 
				PerMachine="yes" 
				Permanent="yes" 
				Vital="yes" 
				DetectCondition="DOT_NET_VER &gt;= v8.0.0" 
				InstallArguments="/norestart /quiet">
                <ExePackagePayload 
					Description="Microsoft .NET 8.0 Desktop Runtime (v8.0.8) - Windows x64" 
					ProductName="Microsoft .NET Desktop Runtime - 8.0.8 (x64)" 					
					DownloadUrl="https://download.visualstudio.microsoft.com/download/pr/907765b0-2bf8-494e-93aa-5ef9553c5d68/a9308dc010617e6716c0e6abd53b05ce/windowsdesktop-runtime-8.0.8-win-x64.exe"
					Hash="27484FFB1E9CE5E6290CDA8F5F49563CF4A9E2692AA57429FCD0D3DE4F30FC2FCE204B1B120349ED50712E95D3FA51037EBAF9B7FD60C41856857B1372E0EAC7"
					Name="windowsdesktop-runtime-8.0.8-win-x64.exe"
					Size="58492592"
					Version="8.0.8.33916"
					/>
            </ExePackage>
        </PackageGroup>
    </Fragment>
</Wix>

[csdahlberg]

I never did confirm exactly what was causing our failures with NetFx462RedistAsPrereq, but comparing your wxs to https://github.com/wixtoolset/wix/blob/main/src/ext/NetFx/wixlib/NetFx462.wxs, I wonder if using Cache="remove" for your ExePackage might do it.

[cornerbowlsoftware]

@csdahlberg I looked at the docs and they state:

remove: Always uncache the package after Cache, Install, Modify, Repair, Uninstall, and Layout.

Which sounds like it's only being used after the cache. I just created an embedded installer that includes the full .net runtime and verified it doesn't try to download anything so I think I'm good now.