diff --git a/.github/workflows/upstream pretest.yaml b/.github/workflows/upstream pretest.yaml
index 2cb23e17..5065822f 100644
--- a/.github/workflows/upstream pretest.yaml	
+++ b/.github/workflows/upstream pretest.yaml	
@@ -299,7 +299,7 @@ jobs:
                 uses: actions/checkout@main
                 with:
                     ref: ${{ github.event.repository.default_branch }}
-                    path: './core'
+                    path: './POCGL' # needs to have exactly this name for consistent traces in err tests
                     fetch-depth: 0
             
             -   name: checkout subm fork
@@ -424,7 +424,7 @@ jobs:
                     
                     
                     Write-Host "Updating main repo..."
-                    Push-Location './core'
+                    Push-Location './POCGL'
                     git fetch --all 2>&1 | Out-Null
                     
                     if (&{ git show-ref --verify -q "refs/remotes/origin/$b_core_subm_pretest"; $? }) {
@@ -467,6 +467,7 @@ jobs:
                     }
                     
                     $core_pretest_sha = git rev-parse HEAD
+                    if (-not $?) { throw "git rev-parse failed" }
                     Pop-Location
                     
                     
@@ -474,6 +475,9 @@ jobs:
                     Write-Host "Adding meta to fork repo..."
                     Push-Location './fork'
                     
+                    $pr_head_sha = git rev-parse "remotes/0_official/pull/$pr_num/head"
+                    if (-not $?) { throw "git rev-parse failed" }
+                    
                     git commit --allow-empty -m @"
                     Add pretest meta
                     meta.pr_head_sha=$pr_head_sha
@@ -509,7 +513,7 @@ jobs:
                     
                     
                     Write-Host "Testing main repo..."
-                    Push-Location './core'
+                    Push-Location './POCGL'
                     
                     & .\DeleteAllTemp.bat NoPause | Out-Null
                     
@@ -554,7 +558,7 @@ jobs:
             -   name: checkout main repo
                 uses: actions/checkout@main
                 with:
-                    path: './core'
+                    path: './POCGL'
                     fetch-depth: 0
                     sparse-checkout-cone-mode: false
                     sparse-checkout: '.gitmodules'
@@ -584,7 +588,7 @@ jobs:
                     
                     
                     
-                    Push-Location './core'
+                    Push-Location './POCGL'
                     
                     $core_removed_pr_nums = @()
                     foreach ($pr_num in $core_pretest_pr_nums) {