[BUG] install.ps1 prints "✅ Installation complete!" even when claude.exe install fails in Windows Powershell -

[dronewai]

irm https://claude.ai/install.ps1 | iex Setting up Claude Code... × Installation failed Checksum mismatch: expected b29dca8880f7bcd8820909cb630f0bace6e8a4a126caa7aafdd5ca2dbd13c497, got e677b695c8418c687d5084cd88012d36be9695e8db59510531023601e4a0deeb Try running with --force to override checks ✅ Installation complete!

Bug Description

The PowerShell installer (install.ps1) prints ✅ Installation complete! even when the installation subprocess fails.

Root cause: The script calls & $binaryPath install $Target (an external process) inside a try/finally block but never checks $LASTEXITCODE after it. In PowerShell, $ErrorActionPreference = "Stop" only applies to cmdlets — it does not throw on non-zero exit codes from external executables. So when claude.exe install fails and exits with a non-zero code, PowerShell silently continues and executes the success message on the next line.

Relevant code in install.ps1:

try {
    & $binaryPath install $Target   # ← fails, exits non-zero
}
finally {
    Remove-Item -Force $binaryPath  # ← cleanup runs (correct)
}

Write-Output "✅ Installation complete!"  # ← BUG: always runs regardless of exit code

Proposed fix:

try {
    if ($Target) {
        & $binaryPath install $Target
    } else {
        & $binaryPath install
    }

    # $ErrorActionPreference = "Stop" does NOT cover external processes.
    # Must check $LASTEXITCODE explicitly for any executable called with &
    if ($LASTEXITCODE -ne 0) {
        Write-Error "Installation failed (claude.exe exited with code $LASTEXITCODE)"
        exit $LASTEXITCODE
    }
}
finally {
    try {
        Start-Sleep -Seconds 1
        Remove-Item -Force $binaryPath
    }
    catch {
        Write-Warning "Could not remove temporary file: $binaryPath"
    }
}

# Only reached if $LASTEXITCODE -eq 0
Write-Output ""
Write-Output "$([char]0x2705) Installation complete!"
Write-Output ""

[github-actions]

Found 3 possible duplicate issues:

1. [BUG] Powershell Native Install does not copy claude.exe #16041
2. [BUG] Native installer reports success but binary missing on Void Linux #20968
3. [BUG] Native installer reports success but fails to install binary on Raspberry Pi (ARM64) #20490

This issue will be automatically closed as a duplicate in 3 days.

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🤖 Generated with Claude Code

[dronewai]

This is not a duplicate of the flagged issues. Here's why:

#16041, #20968, #20490 all report a symptom: "installer prints success but binary is missing." They describe the outcome but don't identify the root cause — they assume the binary wasn't created.

This issue (#26880) is different in two key ways:

1. Different failure mode: Those issues involve claude.exe install silently failing to place the binary. My issue involves claude.exe install explicitly reporting a checksum mismatch failure with a non-zero exit code — a distinct, detectable error condition.

2. Root cause identified with source code: I have read install.ps1 and identified the exact bug: the Write-Output "✅ Installation complete!" line sits outside the try/finally block and is never guarded by a $LASTEXITCODE check. In PowerShell, $ErrorActionPreference = "Stop" does not apply to external executables called with & — so any non-zero exit from claude.exe install is silently ignored and execution falls through to the success message.

3. Proposed fix included: This issue provides a concrete, targeted code fix — not just a symptom report.

The flagged duplicates are downstream symptoms of potentially related but distinct problems. This issue is a specific, source-backed bug report about the install.ps1 wrapper script's error handling, with a fix. Keeping open.

[onlymicki]

Same issue. Get below output but claude.exe is missing.

PS C:\WINDOWS\system32> irm https://claude.ai/install.ps1 | iex
Setting up Claude Code...

✅ Installation complete!

[github-actions]

Closing for now — inactive for too long. Please open a new issue if this is still relevant.

[github-actions]

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.