How do I set a Machine environment variable from a Chocolatey package?

Question

I'm the author of several Chocolatey packages that need to set environment variables as part of the proper "installation" of the package. For example: ANT_HOME, MW_HOME, and JAVA_HOME in the Java ecosystem should point to the installation directory for ant, weblogic, and java, respectively.

And, since Chocolatey is a machine-wide package manager, my thought would be to set these machine-wide (MSDN).

[System.Environment]::SetEnvironmentVariable("JAVA_HOME", "path/to/jre/install", "Machine")

If I just run that, I get the expected permission exception

Exception calling "SetEnvironmentVariable" with "3" argument(s): "Requested registry access is not allowed."

If I run the same command in an elevated prompt, manually, everything works fine. So, I need to invoke it in an elevated prompt. With Chocolatey, you're supposed to use: [Start-ChocolateyProcessAsAdmin][2] like so

Start-ChocolateyProcessAsAdmin @"
[System.Environment]::SetEnvironmentVariable("JAVA_HOME", "path/to/jre/install", "Machine")
"@

It prompts for elevation (I always run in a normal prompt when developing to be sure that it's actually working), but I see red errors flash by and this message with no warning/error

Elevating Permissions and running C:\windows\System32\WindowsPowerShell\v1.0\powershell.exe -NoProfile -ExecutionPolicy unrestricted -Command "& import-module -name 'C:\Chocolatey\chocolateyinstall\helpers\chocolateyInstaller.psm1'; try{[System.Environment]::SetEnvironmentVariable("JAVA_HOME", "path/to/jre/install", "Machine"); start-sleep 6;}catch{write-error 'That was not sucessful';start-sleep 8;throw;}". This may take awhile, depending on the statements.

What gives?

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UPDATE:

Some combination of the following makes it work, mysteriously... adding line-terminators (even to single statements) and wrapping all the arguments in single quotes.

Start-ChocolateyProcessAsAdmin @"
[System.Environment]::SetEnvironmentVariable('JAVA_HOME', 'path/to/jre/install', 'Machine');
"@

I would still like a non-brute-force answer. I'm sure it's a combination of PowerShell's nightmare string quoting/interpreting rules + Chocolatey's invocation.

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UPDATE:

I'm also having trouble with multiple statements, even though I'm separating them!

Start-ChocolateyProcessAsAdmin @"
[System.Environment]::SetEnvironmentVariable('MW_HOME', 'path/to/wl/install', 'Machine');
[System.Environment]::SetEnvironmentVariable('WL_HOME', 'path/to/wl/install/wlserver', 'Machine');
"@

I saw, but did not capture, a Chocolatey log statement on screen that showed one of the line-terminators removed!

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THOUGHT:

I mean, should I just not do this and write an easy "User" environment variable instead? It's not correct! The damn things are installed machine-wide... I don't want to give up yet.

Answer 1

Why not use the built in helper for this, Install-ChocolateyEnvironmentVariable. The usage is quite simple...

Install-ChocolateyEnvironmentVariable 'JAVA_HOME' 'path\to\jre' 'Machine'