diff --git a/.github/workflows/bot-pr-comment.yml b/.github/workflows/bot-pr-comment.yml
index 61952428f3e..0058e25208c 100644
--- a/.github/workflows/bot-pr-comment.yml
+++ b/.github/workflows/bot-pr-comment.yml
@@ -7,11 +7,10 @@ jobs:
     runs-on: ubuntu-latest
     if: github.event.issue.pull_request != '' && github.event.comment.body == 'label!' && (github.event.comment.author_association == 'COLLABORATOR' || github.event.comment.author_association == 'MEMBER' || github.event.comment.author_association == 'OWNER')
     steps:
-    - name: Checkout the latest code
+    - name: Checkout the latest code (shallow clone)
       uses: actions/checkout@v2
       with:
         ref: develop
-        fetch-depth: 0
     - name: Add appropriate labels
       env:
         GITHUB_TOKEN: ${{ secrets.BOT_TOKEN }}
@@ -21,11 +20,10 @@ jobs:
     runs-on: ubuntu-18.04
     if: github.event.issue.pull_request != '' && github.event.comment.body == 'check-format!' && (github.event.comment.author_association == 'COLLABORATOR' || github.event.comment.author_association == 'MEMBER' || github.event.comment.author_association == 'OWNER')
     steps:
-    - name: Checkout the latest code
+    - name: Checkout the latest code (shallow clone)
       uses: actions/checkout@v2
       with:
         ref: develop
-        fetch-depth: 0
     - name: Check for formatting changes
       env:
         GITHUB_TOKEN: ${{ secrets.BOT_TOKEN }}
@@ -41,11 +39,11 @@ jobs:
     runs-on: ubuntu-18.04
     if: github.event.issue.pull_request != '' && github.event.comment.body == 'format!' && (github.event.comment.author_association == 'COLLABORATOR' || github.event.comment.author_association == 'MEMBER' || github.event.comment.author_association == 'OWNER')
     steps:
-    - name: Checkout the latest code
+    - name: Checkout the latest code (shallow clone)
       uses: actions/checkout@v2
       with:
         ref: develop
-        fetch-depth: 0
+        persist-credentials: false
     - name: Commit formatting changes
       env:
         GITHUB_TOKEN: ${{ secrets.BOT_TOKEN }}
@@ -60,6 +58,7 @@ jobs:
       with:
         ref: develop
         fetch-depth: 0
+        persist-credentials: false
     - name: Automatic Rebase
       env:
         GITHUB_TOKEN: ${{ secrets.BOT_TOKEN }}
diff --git a/.github/workflows/bot-pr-created.yml b/.github/workflows/bot-pr-created.yml
index d86d6f5c869..aa306e1f3aa 100644
--- a/.github/workflows/bot-pr-created.yml
+++ b/.github/workflows/bot-pr-created.yml
@@ -8,11 +8,10 @@ jobs:
     runs-on: ubuntu-latest
     if: github.event.pull_request.author_association == 'COLLABORATOR' || github.event.pull_request.author_association == 'MEMBER' || github.event.pull_request.author_association == 'OWNER'
     steps:
-      - name: Checkout the latest code
+      - name: Checkout the latest code (shallow clone)
         uses: actions/checkout@v2
         with:
           ref: develop
-          fetch-depth: 0
       - name: Add appropriate labels
         env:
           GITHUB_TOKEN: ${{ secrets.BOT_TOKEN }}
diff --git a/.github/workflows/bot-pr-updated.yml b/.github/workflows/bot-pr-updated.yml
index b0f0c2e5570..c83d1866b57 100644
--- a/.github/workflows/bot-pr-updated.yml
+++ b/.github/workflows/bot-pr-updated.yml
@@ -8,11 +8,10 @@ jobs:
     runs-on: ubuntu-18.04
     if: github.event.pull_request.author_association == 'COLLABORATOR' || github.event.pull_request.author_association == 'MEMBER' || github.event.pull_request.author_association == 'OWNER'
     steps:
-      - name: Checkout the latest code
+      - name: Checkout the latest code (shallow clone)
         uses: actions/checkout@v2
         with:
           ref: develop
-          fetch-depth: 0
       - name: Check for formatting changes
         env:
           GITHUB_TOKEN: ${{ secrets.BOT_TOKEN }}
diff --git a/.github/workflows/joss.yml b/.github/workflows/joss.yml
index 67d52410466..92aca560633 100644
--- a/.github/workflows/joss.yml
+++ b/.github/workflows/joss.yml
@@ -11,7 +11,9 @@ jobs:
     runs-on: [ubuntu-latest] 
 
     steps:
-    - uses: actions/checkout@v2
+    - name: Checkout the latest code (shallow clone)
+      uses: actions/checkout@v2
+
     - name: setup
       run: sudo apt-get install texlive-xetex pandoc pandoc-citeproc
     - name: info
diff --git a/.github/workflows/osx.yml b/.github/workflows/osx.yml
index 79caf2169a4..5807599e800 100644
--- a/.github/workflows/osx.yml
+++ b/.github/workflows/osx.yml
@@ -21,7 +21,8 @@ jobs:
     runs-on: [macos-latest]
 
     steps:
-    - uses: actions/checkout@v2
+    - name: Checkout the latest code (shallow clone)
+      uses: actions/checkout@v2
 
     - name: setup
       run: |
diff --git a/.github/workflows/windows-cygwin.yml b/.github/workflows/windows-cygwin.yml
index 317e3608253..253a5dd38f6 100644
--- a/.github/workflows/windows-cygwin.yml
+++ b/.github/workflows/windows-cygwin.yml
@@ -20,7 +20,8 @@ jobs:
     runs-on: [windows-latest]
     steps:
     - run: git config --global core.autocrlf input
-    - uses: actions/checkout@v2
+    - name: Checkout the latest code (shallow clone)
+      uses: actions/checkout@v2
 
     - name: setup
       run: |
diff --git a/.github/workflows/windows-mingw.yml b/.github/workflows/windows-mingw.yml
index beeeb34d840..7e774c3cc21 100644
--- a/.github/workflows/windows-mingw.yml
+++ b/.github/workflows/windows-mingw.yml
@@ -19,7 +19,8 @@ jobs:
     name: mingw/${{ matrix.config.name }}
     runs-on: [windows-latest]
     steps:
-    - uses: actions/checkout@v2
+    - name: Checkout the latest code (shallow clone)
+      uses: actions/checkout@v2
 
     - name: Debug over SSH (tmate)
       uses: mxschmitt/action-tmate@v3.5
diff --git a/.github/workflows/windows-msvc-cuda.yml b/.github/workflows/windows-msvc-cuda.yml
index 90b000bfc39..e2c0a3b8c43 100644
--- a/.github/workflows/windows-msvc-cuda.yml
+++ b/.github/workflows/windows-msvc-cuda.yml
@@ -20,7 +20,8 @@ jobs:
     runs-on: [windows-latest]
 
     steps:
-    - uses: actions/checkout@v2
+    - name: Checkout the latest code (shallow clone)
+      uses: actions/checkout@v2
     - name: setup (versioned)
       if: matrix.config.version != 'latest'
       run: |
diff --git a/.github/workflows/windows-msvc-ref.yml b/.github/workflows/windows-msvc-ref.yml
index c2df41390c1..aa11a2ffba1 100644
--- a/.github/workflows/windows-msvc-ref.yml
+++ b/.github/workflows/windows-msvc-ref.yml
@@ -22,7 +22,8 @@ jobs:
     name: msvc/${{ matrix.config.name }}
     runs-on: [windows-latest]
     steps:
-    - uses: actions/checkout@v2
+    - name: Checkout the latest code (shallow clone)
+      uses: actions/checkout@v2
 
     - name: Debug over SSH (tmate)
       uses: mxschmitt/action-tmate@v3.5