Fizzadar
diff --git a/‎.ci/scripts/checkout_complement.sh
+25 b/‎.ci/scripts/checkout_complement.sh
+25
diff --git a/‎.git-blame-ignore-revs
+3 b/‎.git-blame-ignore-revs
+3
diff --git a/‎.github/workflows/tests.yml
+40-20 b/‎.github/workflows/tests.yml
+40-20
@@ -0,0 +1,25 @@
+#!/bin/bash
+#
+# Fetches a version of complement which best matches the current build.
+#
+# The tarball is unpacked into `./complement`.
+
+set -e
+mkdir -p complement
+
+# Pick an appropriate version of complement. Depending on whether this is a PR or release,
+# etc. we need to use different fallbacks:
+#
+# 1. First check if there's a similarly named branch (GITHUB_HEAD_REF
+#    for pull requests, otherwise GITHUB_REF).
+# 2. Attempt to use the base branch, e.g. when merging into release-vX.Y
+#    (GITHUB_BASE_REF for pull requests).
+# 3. Use the default complement branch ("HEAD").
+for BRANCH_NAME in "$GITHUB_HEAD_REF" "$GITHUB_BASE_REF" "${GITHUB_REF#refs/heads/}" "HEAD"; do
+  # Skip empty branch names and merge commits.
+  if [[ -z "$BRANCH_NAME" || $BRANCH_NAME =~ ^refs/pull/.* ]]; then
+    continue
+  fi
+
+  (wget -O - "https://github.com/matrix-org/complement/archive/$BRANCH_NAME.tar.gz" | tar -xz --strip-components=1 -C complement) && break
+done
@@ -6,3 +6,6 @@ aff1eb7c671b0a3813407321d2702ec46c71fa56
 
 # Update black to 20.8b1 (#9381).
 0a00b7ff14890987f09112a2ae696c61001e6cf1
+
+# Convert tests/rest/admin/test_room.py to unix file endings (#7953).
+c4268e3da64f1abb5b31deaeb5769adb6510c0a7
@@ -306,7 +306,7 @@ jobs:
       - run: .ci/scripts/test_synapse_port_db.sh
 
   complement:
-    if: ${{ !failure() && !cancelled() }}
+    if: "${{ !failure() && !cancelled() }}"
     needs: linting-done
     runs-on: ubuntu-latest
 
@@ -333,30 +333,50 @@ jobs:
       # Attempt to check out the same branch of Complement as the PR. If it
       # doesn't exist, fallback to HEAD.
       - name: Checkout complement
+        run: synapse/.ci/scripts/checkout_complement.sh
+
+      - run: |
+          set -o pipefail
+          COMPLEMENT_DIR=`pwd`/complement synapse/scripts-dev/complement.sh -json 2>&1 | gotestfmt
         shell: bash
+        name: Run Complement Tests
+
+  # We only run the workers tests on `develop` for now, because they're too slow to wait for on PRs.
+  # Sadly, you can't have an `if` condition on the value of a matrix, so this is a temporary, separate job for now.
+  # GitHub Actions doesn't support YAML anchors, so it's full-on duplication for now.
+  complement-developonly:
+    if: "${{ !failure() && !cancelled() && (github.ref == 'refs/heads/develop') }}"
+    needs: linting-done
+    runs-on: ubuntu-latest
+
+    steps:
+      # The path is set via a file given by $GITHUB_PATH. We need both Go 1.17 and GOPATH on the path to run Complement.
+      # See https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#adding-a-system-path
+      - name: "Set Go Version"
         run: |
-          mkdir -p complement
-          # Attempt to use the version of complement which best matches the current
-          # build. Depending on whether this is a PR or release, etc. we need to
-          # use different fallbacks.
-          #
-          # 1. First check if there's a similarly named branch (GITHUB_HEAD_REF
-          #    for pull requests, otherwise GITHUB_REF).
-          # 2. Attempt to use the base branch, e.g. when merging into release-vX.Y
-          #    (GITHUB_BASE_REF for pull requests).
-          # 3. Use the default complement branch ("HEAD").
-          for BRANCH_NAME in "$GITHUB_HEAD_REF" "$GITHUB_BASE_REF" "${GITHUB_REF#refs/heads/}" "HEAD"; do
-            # Skip empty branch names and merge commits.
-            if [[ -z "$BRANCH_NAME" || $BRANCH_NAME =~ ^refs/pull/.* ]]; then
-              continue
-            fi
-
-            (wget -O - "https://github.com/matrix-org/complement/archive/$BRANCH_NAME.tar.gz" | tar -xz --strip-components=1 -C complement) && break
-          done
+          # Add Go 1.17 to the PATH: see https://github.com/actions/virtual-environments/blob/main/images/linux/Ubuntu2004-Readme.md#environment-variables-2
+          echo "$GOROOT_1_17_X64/bin" >> $GITHUB_PATH
+          # Add the Go path to the PATH: We need this so we can call gotestfmt
+          echo "~/go/bin" >> $GITHUB_PATH
+
+      - name: "Install Complement Dependencies"
+        run: |
+          sudo apt-get update && sudo apt-get install -y libolm3 libolm-dev
+          go get -v github.com/haveyoudebuggedit/gotestfmt/v2/cmd/gotestfmt@latest
+
+      - name: Run actions/checkout@v2 for synapse
+        uses: actions/checkout@v2
+        with:
+          path: synapse
+
+      # Attempt to check out the same branch of Complement as the PR. If it
+      # doesn't exist, fallback to HEAD.
+      - name: Checkout complement
+        run: synapse/.ci/scripts/checkout_complement.sh
 
       - run: |
           set -o pipefail
-          COMPLEMENT_DIR=`pwd`/complement synapse/scripts-dev/complement.sh -json 2>&1 | gotestfmt
+          WORKERS=1 COMPLEMENT_DIR=`pwd`/complement synapse/scripts-dev/complement.sh -json 2>&1 | gotestfmt
         shell: bash
         name: Run Complement Tests