[EwoutH]

The documented Windows one-liner fails before installing anything:

PS> irm https://raw.githubusercontent.com/quarto-dev/q2/main/install.ps1 | iex
iex : The attribute cannot be added because variable Platform with value  would no longer be valid.
    + FullyQualifiedErrorId : ValidateSetFailure,Microsoft.PowerShell.Commands.InvokeExpressionCommand

Cause

Invoke-Expression doesn't run the text as a script with parameters; the param(...) block executes as ordinary variable declarations. The [ValidateSet('windows_amd64', 'windows_arm64')] on -Platform (added in v0.38.0) is then attached to a variable whose value is empty, which the set rejects. Minimal repro:

$s = "param([ValidateSet('a','b')][string]`$Platform)`n'ok'"
Invoke-Expression $s                 # ValidateSetFailure
& ([scriptblock]::Create($s))        # ok

CI didn't catch it because the nightly install smoke uses the scriptblock form (& ([scriptblock]::Create((irm …))) -Nightly), which binds parameters normally.

Changes

• install.ps1: drop the [ValidateSet] and validate -Platform by hand after Die is defined, with the same accepted values and a clear error.
• nightly.yml: add an install-smoke step (Windows PowerShell 5.1) that runs the literal irm … | iex one-liner. It installs the latest stable release to the default %USERPROFILE%\.local\bin and checks that q2.exe --version runs.

Verification (Windows 11, Windows PowerShell 5.1)

• Get-Content -Raw install.ps1 | Invoke-Expression (with USERPROFILE pointed at a scratch dir): installs v0.42.0, checksum verified, q2 (quarto 2) 0.42.0.
• -Platform bogus via the scriptblock form: q2 install: unknown -Platform 'bogus' (expected windows_amd64 or windows_arm64).
• -Platform windows_amd64 -Dest <dir> via the scriptblock form: installs normally.

Until this lands, the workaround is & ([scriptblock]::Create((irm https://raw.githubusercontent.com/quarto-dev/q2/main/install.ps1))).

[posit-snyk-bot]

✅ Snyk checks have passed. No issues have been found so far.

Status	Scan Engine	Critical	High	Medium	Low	Total (0)
✅	Open Source Security	0	0	0	0	0 issues
✅	Licenses	0	0	0	0	0 issues

💻 Catch issues earlier using the plugins for VS Code, JetBrains IDEs, Visual Studio, and Eclipse.

[cscheid]

I'm going to let @cderv handle the review on this one.