diagnostic: probe Get-FileHash resolution on windows-latest (not for merge)

Author: jatassi

.github/workflows/upgrade-windows.yml

@@ -1,19 +1,6 @@
-# Hand-authored (unlike release.yml, which is cargo-dist-generated and must not
-# be hand-edited). Exercises the real Windows rename-aside swap that the
-# `upgrade` fixture test performs — the-loop's own dev machines have no
-# Windows box, so this is the only place that leg runs.
-#
-# Pinned fact (design-time, cargo-dist 0.32.0): the PowerShell installer
-# performs no checksum verification at all (the-loop-installer.ps1) — only
-# the shell installer does. So this job proves the Windows rename-aside swap
-# works, not the sha256 checksum bar; the corrupt-archive case in
-# upgrade_fixture.rs asserts an unpack failure on Windows instead of a
-# checksum mismatch, for exactly that reason.
-#
-# This job's greenness is a release-gate ready check (see the Release
-# runbook in docs/architecture.md), not a validate-time assertion — it only
-# runs at workflow_dispatch or on push to main, never on feature-branch
-# pushes or pull requests.
+# TEMPORARY DIAGNOSTIC VERSION — branch diagnose/windows-fixture-hash.
+# Probes why `Get-FileHash` comes back CommandNotFoundException inside the
+# upgrade fixture. Not for merge; the real file lives on main.
 name: upgrade-windows
 
 on:
@@ -28,4 +15,54 @@ jobs:
     steps:
       - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@stable
-      - run: cargo test --package the-loop --features upgrade --test upgrade_fixture
+
+      - name: A - what shell does a bare run step get
+        continue-on-error: true
+        run: |
+          Write-Host "PSEdition=$($PSVersionTable.PSEdition) PSVersion=$($PSVersionTable.PSVersion)"
+          Write-Host "--- parent PSModulePath ---"
+          $env:PSModulePath -split ';' | ForEach-Object { Write-Host "  $_" }
+          Write-Host "--- Get-FileHash resolvable in parent? ---"
+          Write-Host (Get-Command Get-FileHash -ErrorAction SilentlyContinue | Out-String)
+
+      - name: B - the exact failing call, powershell child inheriting parent env
+        continue-on-error: true
+        run: |
+          Set-Content -Path probe.bin -Value 'hello'
+          Write-Host "--- child powershell PSVersion ---"
+          powershell -NoProfile -Command 'Write-Host $PSVersionTable.PSVersion'
+          Write-Host "--- child powershell PSModulePath ---"
+          powershell -NoProfile -Command '$env:PSModulePath -split ";" | ForEach-Object { Write-Host "  $_" }'
+          Write-Host "--- child powershell Get-FileHash (the failing call) ---"
+          powershell -NoProfile -Command "(Get-FileHash -Algorithm SHA256 -LiteralPath 'probe.bin').Hash.ToLower()"
+          Write-Host "exit=$LASTEXITCODE"
+
+      - name: C - candidate fix 1, pwsh child instead of powershell
+        continue-on-error: true
+        run: |
+          pwsh -NoProfile -Command "(Get-FileHash -Algorithm SHA256 -LiteralPath 'probe.bin').Hash.ToLower()"
+          Write-Host "exit=$LASTEXITCODE"
+
+      - name: D - candidate fix 2, powershell child with PSModulePath cleared
+        continue-on-error: true
+        run: |
+          $env:PSModulePath = ''
+          powershell -NoProfile -Command "(Get-FileHash -Algorithm SHA256 -LiteralPath 'probe.bin').Hash.ToLower()"
+          Write-Host "exit=$LASTEXITCODE"
+
+      - name: E - candidate fix 3, powershell child with system module path restored
+        continue-on-error: true
+        run: |
+          $env:PSModulePath = "$env:SystemRoot\system32\WindowsPowerShell\v1.0\Modules"
+          powershell -NoProfile -Command "(Get-FileHash -Algorithm SHA256 -LiteralPath 'probe.bin').Hash.ToLower()"
+          Write-Host "exit=$LASTEXITCODE"
+
+      - name: F - certutil as a shell-free fallback
+        continue-on-error: true
+        run: |
+          certutil -hashfile probe.bin SHA256
+          Write-Host "exit=$LASTEXITCODE"
+
+      - name: G - the actual suite, current state
+        continue-on-error: true
+        run: cargo test --package the-loop --features upgrade --test upgrade_fixture