Paliak · AdamZ-8113 · Sep 7, 2026
diff --git a/.gitattributes b/.gitattributes
@@ -2,6 +2,7 @@
 # Set default behavior to automatically normalize line endings.
 ###############################################################################
 * text=auto
+*.sh text eol=lf
 
 ###############################################################################
 # Set default behavior for command prompt diff.

diff --git a/.github/workflows/buildtest.yml b/.github/workflows/buildtest.yml
@@ -1,93 +1,79 @@
----
-name: Run Tests
+name: Compare saved builds
 on:
   pull_request:
-    branches:
-      - dev
+    branches: [dev, tests-branch]
   workflow_dispatch:
+    inputs:
+      base_ref:
+        description: Base commit or ref (empty uses this workflow's commit)
+        type: string
+      head_ref:
+        description: Candidate commit or ref (empty uses this workflow's commit)
+        type: string
+      strict:
+        description: Fail on stat differences as well as calculation errors
+        type: boolean
+        default: false
+permissions:
+  contents: read
 concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
+  group: build-corpus-${{ github.ref }}
   cancel-in-progress: true
 jobs:
-  run_build_diff:
+  fixture_smoke:
+    name: Fixed fixture comparison
     runs-on: ubuntu-latest
+    timeout-minutes: 30
     steps:
-      - name: Checkout HEAD
-        uses: actions/checkout@v4
-      - name: Fetch Dev branch
-        id: get-dev-ref
-        run: |
-            git fetch --depth=1 origin dev
-            echo "devref=$(git rev-parse origin/dev)" >> $GITHUB_OUTPUT
-      - name: Download Dev branch cache
-        id: download-dev-ref-cache
-        uses: dawidd6/action-download-artifact@3ecf4024886f219d9290351234889bfb45d1b9da
-        with:
-          name: cache-devref-${{ steps.get-dev-ref.outputs.devref }}
-          path: /tmp/cache/
-          if_no_artifact_found: warn
-          search_artifacts: true
-      # Dev ref cache contains the build list and build xmls. Use that one to keep tests reproducible
-      - name: Update static builds list from cache
-        if: ${{ steps.download-dev-ref-cache.outputs.found_artifact == 'true' }}
-        run: cat /tmp/cache/builds.txt > spec/builds.txt
-      - name: Download latest build list
-        if: ${{ steps.download-dev-ref-cache.outputs.found_artifact == 'false' }}
-        id: download-build-list
-        uses: dawidd6/action-download-artifact@3ecf4024886f219d9290351234889bfb45d1b9da
+      - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
         with:
-          name: builds.txt
-          path: /tmp/latestbuildlist/
-          workflow: updatebuildlist.yml
-          if_no_artifact_found: warn
-          search_artifacts: true
-      - name: Update static builds list
-        if: ${{ steps.download-dev-ref-cache.outputs.found_artifact == 'false' && steps.download-build-list.outputs.found_artifact == 'true' }}
-        run: cat /tmp/latestbuildlist/builds.txt > spec/builds.txt
-      - name: Download latest build xmls
-        if: ${{ steps.download-dev-ref-cache.outputs.found_artifact == 'false' }}
-        uses: dawidd6/action-download-artifact@3ecf4024886f219d9290351234889bfb45d1b9da
+          fetch-depth: 0
+          persist-credentials: false
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
         with:
-          name: build-xmls
-          path: /tmp/cache/
-          if_no_artifact_found: warn
-          search_artifacts: true
-      - name: Calculate build xmls and differences between them
+          python-version: '3.12'
+      - name: Compare every fixed fixture on base and candidate
+        env:
+          BASE_REF: ${{ github.event.pull_request.base.sha || inputs.base_ref || github.sha }}
+          HEAD_REF: ${{ github.event.pull_request.head.sha || inputs.head_ref || github.sha }}
+          STRICT_DIFF: ${{ inputs.strict }}
         run: |
-            mkdir /tmp/cache || true # Make sure /tmp/cache exists. Ignore exit code
-            chmod -R 777 /tmp/cache && docker compose run -v '/tmp/cache/:/cache' -e 'CACHEDIR=/cache' busted-diff | tee /tmp/dockerlog
-      - name: Generate artefact
+          args=()
+          if [ "$STRICT_DIFF" = true ]; then args+=(--strict); fi
+          python spec/RunBuildDiff.py --base "$BASE_REF" --head "$HEAD_REF" --fixtures-only --output "$RUNNER_TEMP/fixture-diff" "${args[@]}"
+      - name: Run importer and runner contract tests
         run: |
-          sed -n '/Runtime comparison for/,/Savefile Diff for/{/Savefile Diff for/!p;}' /tmp/dockerlog > /tmp/artefact
-          sed -n '/Savefile Diff for/, $p' /tmp/dockerlog >> /tmp/artefact
-          [ -s /tmp/artefact ] || rm /tmp/artefact
-      - name: Upload artefact
-        uses: actions/upload-artifact@v4
-        with:
-          name: build-diff-output
-          path: /tmp/artefact
-      - name: Save used build list into cache
-        if: ${{ steps.download-dev-ref-cache.outputs.found_artifact == 'false' }}
-        run: cp spec/builds.txt /tmp/cache/
-      - name: Move xmls found in builds.txt to a new directory
-        if: ${{ steps.download-dev-ref-cache.outputs.found_artifact == 'false' && steps.download-build-list.outputs.found_artifact == 'true' }}
+          python -m unittest discover -s tests -p 'test_update_build_corpus.py' -v
+          python -m unittest discover -s tests -p 'test_build_diff_contract.py' -v
+      - name: Test output comparison semantics
         run: |
-          mkdir new-build-xmls
-          while IFS= read -r line; do
-              FILENAME="/tmp/cache/${line//[^a-zA-Z0-9]/}.xml"
-              if [ -f "$FILENAME" ]; then
-                  mv "$FILENAME" "./new-build-xmls/"
-              fi
-          done < "spec/builds.txt"
-      - name: Upload new build xmls
-        if: ${{ steps.download-dev-ref-cache.outputs.found_artifact == 'false' && steps.download-build-list.outputs.found_artifact == 'true' }}
-        uses: actions/upload-artifact@v4
+          docker build -t pob-corpus-contracts -f Dockerfile.test-builds .
+          docker run --rm --network none --mount "type=bind,source=$PWD,target=/workdir,readonly" -w /workdir pob-corpus-contracts luajit tests/test_diff_output.lua
+  corpus_comparison:
+    name: Complete rotating corpus comparison
+    if: vars.TEST_BUILD_CORPUS_ENABLED == 'true' || github.event_name == 'workflow_dispatch'
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    steps:
+      - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
         with:
-          name: build-xmls
-          path: './new-build-xmls/*'
-      - name: Upload dev ref cache
-        if: ${{ steps.download-dev-ref-cache.outputs.found_artifact == 'false' }}
-        uses: actions/upload-artifact@v4
+          fetch-depth: 0
+          persist-credentials: false
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
         with:
-          name: cache-devref-${{ steps.get-dev-ref.outputs.devref }}
-          path: /tmp/cache/
+          python-version: '3.12'
+      - name: Pin saved corpus once
+        run: |
+          git fetch origin refs/heads/build-test-corpus
+          CORPUS_SHA=$(git rev-parse FETCH_HEAD)
+          echo "Pinned corpus commit: $CORPUS_SHA"
+          git worktree add --detach "$RUNNER_TEMP/corpus" "$CORPUS_SHA"
+      - name: Calculate all saved inputs without provider requests
+        env:
+          BASE_REF: ${{ github.event.pull_request.base.sha || inputs.base_ref || github.sha }}
+          HEAD_REF: ${{ github.event.pull_request.head.sha || inputs.head_ref || github.sha }}
+          STRICT_DIFF: ${{ inputs.strict }}
+        run: |
+          args=()
+          if [ "$STRICT_DIFF" = true ]; then args+=(--strict); fi
+          python spec/RunBuildDiff.py --base "$BASE_REF" --head "$HEAD_REF" --corpus "$RUNNER_TEMP/corpus" --output "$RUNNER_TEMP/corpus-diff" "${args[@]}"
diff --git a/.github/workflows/unittest.yml b/.github/workflows/unittest.yml
@@ -4,14 +4,20 @@ on:
   push:
     branches:
       - dev
+      - tests-branch
   pull_request:
     branches:
       - dev
+      - tests-branch
+permissions:
+  contents: read
 jobs:
   run_unit_tests:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
+        with:
+          persist-credentials: false
       - name: Run busted tests
         run: docker compose run --no-TTY busted-tests
diff --git a/.github/workflows/updatebuildlist.yml b/.github/workflows/updatebuildlist.yml
@@ -1,37 +1,47 @@
----
-name: Update build list for tests
+name: Refresh monthly build corpus
 on:
   schedule:
     - cron: '20 4 * * *'
   workflow_dispatch:
+permissions:
+  contents: write
+concurrency:
+  group: monthly-build-corpus-writer
+  cancel-in-progress: false
 jobs:
-  update-builds-list:
-    runs-on: ubuntu-22.04
+  refresh:
+    if: github.event_name == 'workflow_dispatch' || (vars.TEST_BUILD_CORPUS_ENABLED == 'true' && github.ref_name == github.event.repository.default_branch)
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
     steps:
-      - name: Checkout HEAD
-        uses: actions/checkout@v4
-      - name: Install moreutils
-        run: sudo apt-get install -y moreutils
-      - name: Download latest build list
-        uses: dawidd6/action-download-artifact@3ecf4024886f219d9290351234889bfb45d1b9da
+      - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
         with:
-          name: builds.txt
-          if_no_artifact_found: warn
-          path: /tmp/latestbuildlist/
-      - name: Update list
-        run: >
-            cat spec/builds.txt /tmp/latestbuildlist/builds.txt
-            <({ curl "https://pobarchives.com/api/builds?q=latest" & curl "https://pobarchives.com/api/builds?q=trending"; }
-            | jq -r '.builds[].build_info.build_link')
-            | tail -n 500
-            | sort -u
-            | sponge builds.txt
-      - name: Print new builds list
-        run: cat builds.txt
-      - name: Save new build list
-        uses: actions/upload-artifact@v4
-        with:
-          name: builds.txt
-          path: builds.txt
-          overwrite: true
-          retention-days: 3
+          python-version: '3.12'
+      - name: Load saved corpus or bootstrap an empty branch
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          REMOTE_REF=$(git ls-remote origin refs/heads/build-test-corpus)
+          if [ -n "$REMOTE_REF" ]; then
+            git fetch origin refs/heads/build-test-corpus
+            git worktree add --detach "$RUNNER_TEMP/corpus" FETCH_HEAD
+          else
+            git worktree add --detach "$RUNNER_TEMP/corpus" HEAD
+            git -C "$RUNNER_TEMP/corpus" switch --orphan build-test-corpus
+          fi
+      - name: Validate and construct next corpus
+        run: python spec/UpdateBuildCorpus.py --url https://api.pob.codes/test-builds --prior "$RUNNER_TEMP/corpus" --output "$RUNNER_TEMP/next-corpus"
+      - name: Commit manifest and retained bytes together
+        run: |
+          git -C "$RUNNER_TEMP/corpus" rm -r --ignore-unmatch codes manifest.json
+          cp -a "$RUNNER_TEMP/next-corpus/." "$RUNNER_TEMP/corpus/"
+          git -C "$RUNNER_TEMP/corpus" add manifest.json codes
+          if git -C "$RUNNER_TEMP/corpus" diff --cached --quiet; then
+            echo "Monthly batch already applied; no corpus change."
+            exit 0
+          fi
+          git -C "$RUNNER_TEMP/corpus" commit -m "Refresh monthly test-build corpus"
+          # Plain fast-forward push rejects a competing writer. The next daily run
+          # refetches/reapplies; never force-push or publish a partial manifest.
+          git -C "$RUNNER_TEMP/corpus" push origin HEAD:refs/heads/build-test-corpus
diff --git a/.gitignore b/.gitignore
@@ -14,6 +14,8 @@ Builds/
 Settings.xml
 
 # Testing
+__pycache__/
+*.pyc
 luajit/
 spec/test_results.log
 spec/test_generation.log
@@ -35,4 +37,4 @@ src/Export/ggpk/*.dll
 src/Data/TimelessJewelData/*.bin
 
 # Simplegraphic Debugging
-runtime/imgui.ini
+runtime/imgui.ini
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -1,5 +1,8 @@
 # Contributing to Path of Building
 
+For the monthly test-build feed, local calculation comparisons, and CI activation,
+see [Build corpus CI](docs/build-corpus-ci.md).
+
 # Table of contents
 1. [Reporting bugs](#reporting-bugs)
 2. [Requesting features](#requesting-features)

diff --git a/Dockerfile.test-builds b/Dockerfile.test-builds
@@ -0,0 +1,7 @@
+FROM ghcr.io/pathofbuildingcommunity/pathofbuilding-tests@sha256:171dc3da232b8c874882e4ae3b3aa4a6e130a6c9450a31904b312435a6bf5daf AS modern_luajit
+FROM ghcr.io/paliak/busted-tests@sha256:0ce3f27d276dd6918d78ae11339e4135c445ea0e4fd31dbc88087ea25232ed90
+RUN luarocks install luautf8 0.1.6-1
+# Retain the existing test dependencies, but use upstream's GC64-capable LuaJIT.
+COPY --from=modern_luajit /usr/local/bin/luajit-2.1.1784580905 /usr/local/bin/luajit-current
+COPY --from=modern_luajit /usr/local/share/luajit-2.1 /usr/local/share/luajit-2.1
+RUN ln -sf /usr/local/bin/luajit-current /usr/local/bin/luajit
diff --git a/Dockerfile.test-builds.dockerignore b/Dockerfile.test-builds.dockerignore
@@ -0,0 +1,2 @@
+**
+!Dockerfile.test-builds