Use Dev Drive for Windows CI

Configure Windows Rust CI jobs and the shared Bazel CI setup to put temp, repository-cache, and output-root paths on the runner's fast work drive when available. Fall back to C: if no secondary drive or Dev Drive provisioning path is available. Co-authored-by: Codex <noreply@openai.com>
2026-05-15 16:53:05 +00:00 · 2026-05-07 14:39:10 -07:00
parent 5815dd6a4b
commit 077a3970d7
3 changed files with 85 additions and 6 deletions
--- a/.github/scripts/setup-dev-drive.ps1
+++ b/.github/scripts/setup-dev-drive.ps1
@@ -0,0 +1,62 @@
+# Configure a fast drive for Windows CI jobs.
+#
+# GitHub-hosted Windows runners do not always expose a secondary D: volume. When
+# they do not, try to create a Dev Drive VHD and fall back to C: if the runner
+# image does not allow that provisioning path.
+
+function Use-FallbackDrive {
+    param([string]$Reason)
+
+    Write-Warning "$Reason Falling back to C:"
+    return "C:"
+}
+
+function Invoke-BestEffort {
+    param([scriptblock]$Script, [string]$Description)
+
+    try {
+        & $Script
+    } catch {
+        Write-Warning "$Description failed: $($_.Exception.Message)"
+    }
+}
+
+if (Test-Path "D:\") {
+    Write-Output "Using existing drive at D:"
+    $Drive = "D:"
+} else {
+    try {
+        $VhdPath = Join-Path $env:RUNNER_TEMP "codex-dev-drive.vhdx"
+        $SizeBytes = 64GB
+
+        if (Test-Path $VhdPath) {
+            Remove-Item -Path $VhdPath -Force
+        }
+
+        New-VHD -Path $VhdPath -SizeBytes $SizeBytes -Dynamic -ErrorAction Stop | Out-Null
+        $Mounted = Mount-VHD -Path $VhdPath -Passthru -ErrorAction Stop
+        $Disk = $Mounted | Get-Disk -ErrorAction Stop
+        $Disk | Initialize-Disk -PartitionStyle GPT -ErrorAction Stop
+        $Partition = $Disk | New-Partition -AssignDriveLetter -UseMaximumSize -ErrorAction Stop
+        $Volume = $Partition | Format-Volume -FileSystem ReFS -NewFileSystemLabel "CodexDevDrive" -DevDrive -Confirm:$false -Force -ErrorAction Stop
+
+        $Drive = "$($Volume.DriveLetter):"
+
+        Invoke-BestEffort { fsutil devdrv trust $Drive } "Trusting Dev Drive $Drive"
+        Invoke-BestEffort { fsutil devdrv enable /disallowAv } "Disabling AV filter attachment for Dev Drives"
+        Invoke-BestEffort { fsutil devdrv query $Drive } "Querying Dev Drive $Drive"
+
+        Write-Output "Using Dev Drive at $Drive"
+    } catch {
+        $Drive = Use-FallbackDrive "Failed to create Dev Drive: $($_.Exception.Message)"
+    }
+}
+
+$Tmp = "$Drive\codex-tmp"
+New-Item -Path $Tmp -ItemType Directory -Force | Out-Null
+
+@(
+    "DEV_DRIVE=$Drive"
+    "TMP=$Tmp"
+    "TEMP=$Tmp"
+) | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append