diff --git a/.github/workflows/ci_sh_def.yml b/.github/workflows/ci_sh_def.yml
index ad016a2b5..6a8eed004 100644
--- a/.github/workflows/ci_sh_def.yml
+++ b/.github/workflows/ci_sh_def.yml
@@ -22,6 +22,13 @@ on:
       - smart_holder
       - v*
 
+concurrency:
+  group: test-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  PIP_ONLY_BINARY: numpy
+
 jobs:
   # This is the "main" test suite, which tests a large number of different
   # versions of default compilers and Python versions in GitHub Actions.
@@ -31,13 +38,14 @@ jobs:
       matrix:
         runs-on: [ubuntu-latest, windows-latest, macos-latest]
         python:
-        - 2.7
-        - 3.5
-        - 3.6
-        - 3.9
-        - 3.10-dev
-        - pypy2
-        - pypy3
+        - '2.7'
+        - '3.5'
+        - '3.6'
+        - '3.9'
+        - '3.10'
+        # - '3.11-dev'
+        - 'pypy-3.7-v7.3.5'
+        # - 'pypy-3.8'
 
         # Items in here will either be added to the build matrix (if not
         # present), or add new keys to an existing matrix element if all the
@@ -55,18 +63,8 @@ jobs:
             python: 3.6
             args: >
               -DPYBIND11_FINDPYTHON=ON
-
-        # These items will be removed from the build matrix, keys must match.
-        exclude:
-            # Currently 32bit only, and we build 64bit
-          - runs-on: windows-latest
-            python: pypy2
-          - runs-on: windows-latest
-            python: pypy3
-
-          # TODO: PyPy2 7.3.3 segfaults, while 7.3.2 was fine.
-          - runs-on: ubuntu-latest
-            python: pypy2
+          - runs-on: macos-latest
+            python: pypy-2.7
 
     name: "🐍 ${{ matrix.python }} • ${{ matrix.runs-on }} • x64 ${{ matrix.args }}"
     runs-on: ${{ matrix.runs-on }}
@@ -102,7 +100,8 @@ jobs:
         key: ${{ runner.os }}-pip-${{ matrix.python }}-x64-${{ hashFiles('tests/requirements.txt') }}
 
     - name: Prepare env
-      run: python -m pip install -r tests/requirements.txt --prefer-binary
+      run: |
+        python -m pip install -r tests/requirements.txt
 
     - name: Setup annotations on Linux
       if: runner.os == 'Linux'
@@ -127,7 +126,7 @@ jobs:
 
     - name: C++11 tests
       # TODO: Figure out how to load the DLL on Python 3.8+
-      if: "!(runner.os == 'Windows' && (matrix.python == 3.8 || matrix.python == 3.9 || matrix.python == '3.10-dev'))"
+      if: "!(runner.os == 'Windows' && (matrix.python == 3.8 || matrix.python == 3.9 || matrix.python == '3.10' || matrix.python == '3.11-dev' || matrix.python == 'pypy-3.8'))"
       run: cmake --build .  --target cpptest -j 2
 
     - name: Interface test C++11
@@ -156,7 +155,7 @@ jobs:
 
     - name: C++ tests
       # TODO: Figure out how to load the DLL on Python 3.8+
-      if: "!(runner.os == 'Windows' && (matrix.python == 3.8 || matrix.python == 3.9 || matrix.python == '3.10-dev'))"
+      if: "!(runner.os == 'Windows' && (matrix.python == 3.8 || matrix.python == 3.9 || matrix.python == '3.10' || matrix.python == '3.11-dev' || matrix.python == 'pypy-3.8'))"
       run: cmake --build build2 --target cpptest
 
     # Third build - C++17 mode with unstable ABI
@@ -208,11 +207,12 @@ jobs:
       fail-fast: false
       matrix:
         include:
-        - python-version: 3.9
+        # TODO: Fails on 3.10, investigate
+        - python-version: "3.9"
           python-debug: true
           valgrind: true
-        - python-version: 3.10-dev
-          python-debug: false
+      # - python-version: "3.11-dev"
+      #   python-debug: false
 
     name: "🐍 ${{ matrix.python-version }}${{ matrix.python-debug && '-dbg' || '' }} (deadsnakes)${{ matrix.valgrind && ' • Valgrind' || '' }} • x64"
     runs-on: ubuntu-latest
@@ -256,7 +256,8 @@ jobs:
         sudo apt-get install libc6-dbg  # Needed by Valgrind
 
     - name: Prepare env
-      run: python -m pip install -r tests/requirements.txt --prefer-binary
+      run: |
+        python -m pip install -r tests/requirements.txt
 
     - name: Configure
       run: >
@@ -537,7 +538,7 @@ jobs:
     - name: Install dependencies
       run: |
         set +e; source /opt/intel/oneapi/setvars.sh; set -e
-        python3 -m pip install -r tests/requirements.txt --prefer-binary
+        python3 -m pip install -r tests/requirements.txt
 
     - name: Configure C++11
       run: |
@@ -630,7 +631,8 @@ jobs:
       run: python3 -m pip install --upgrade pip
 
     - name: Install dependencies
-      run: python3 -m pip install cmake -r tests/requirements.txt --prefer-binary
+      run: |
+        python3 -m pip install cmake -r tests/requirements.txt
 
     - name: VAR_BUILD_TYPE 7
       if: matrix.centos == 7
@@ -759,8 +761,7 @@ jobs:
         - 3.7
         - 3.8
         - 3.9
-        - pypy3
-        # TODO: fix hang on pypy2
+        - pypy-3.6
 
         include:
           - python: 3.9
@@ -789,7 +790,8 @@ jobs:
         arch: x86
 
     - name: Prepare env
-      run: python -m pip install -r tests/requirements.txt --prefer-binary
+      run: |
+        python -m pip install -r tests/requirements.txt
 
     # First build - C++11 mode and inplace
     - name: Configure ${{ matrix.args }}
@@ -836,7 +838,8 @@ jobs:
         toolset: 14.0
 
     - name: Prepare env
-      run: python -m pip install -r tests/requirements.txt --prefer-binary
+      run: |
+        python -m pip install -r tests/requirements.txt
 
     # First build - C++11 mode and inplace
     - name: Configure
@@ -867,13 +870,16 @@ jobs:
           - 3.7
         std:
           - 14
-        args: [ -DCMAKE_CXX_FLAGS="/GR /EHsc /DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT" ]
 
         include:
           - python: 2.7
             std: 17
             args: >
               -DCMAKE_CXX_FLAGS="/permissive- /EHsc /GR /DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT"
+          - python: 3.7
+            std: 17
+            args: >
+              -DCMAKE_CXX_FLAGS="/permissive- /EHsc /GR /DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT"
 
     steps:
     - uses: actions/checkout@v2
@@ -887,7 +893,8 @@ jobs:
       uses: jwlawson/actions-setup-cmake@v1.11
 
     - name: Prepare env
-      run: python -m pip install -r tests/requirements.txt --prefer-binary
+      run: |
+        python -m pip install -r tests/requirements.txt
 
     # First build - C++11 mode and inplace
     - name: Configure
@@ -919,7 +926,8 @@ jobs:
           - { sys: mingw64, env: x86_64 }
           - { sys: mingw32, env: i686 }
     steps:
-    - uses: msys2/setup-msys2@v2
+    # Force version because of https://github.com/msys2/setup-msys2/issues/167
+    - uses: msys2/setup-msys2@v2.4.2
       with:
         msystem: ${{matrix.sys}}
         install: >-
diff --git a/.github/workflows/ci_sh_def.yml.patch b/.github/workflows/ci_sh_def.yml.patch
index 4bdb2fc21..4eecc4e1e 100644
--- a/.github/workflows/ci_sh_def.yml.patch
+++ b/.github/workflows/ci_sh_def.yml.patch
@@ -1,5 +1,5 @@
---- ci.yml	2021-10-11 13:18:34.061740320 -0700
-+++ ci_sh_def.yml	2021-10-11 13:20:02.319713610 -0700
+--- ci.yml	2021-10-26 12:10:34.834324858 -0700
++++ ci_sh_def.yml	2021-10-26 12:12:26.000136653 -0700
 @@ -1,4 +1,16 @@
 -name: CI-SH-AVL
 +# PLEASE KEEP THIS GROUP OF FILES IN SYNC AT ALL TIMES:
@@ -18,7 +18,7 @@
  
  on:
    workflow_dispatch:
-@@ -104,6 +116,7 @@
+@@ -103,6 +115,7 @@
          -DDOWNLOAD_CATCH=ON
          -DDOWNLOAD_EIGEN=ON
          -DCMAKE_CXX_STANDARD=11
@@ -26,7 +26,7 @@
          ${{ matrix.args }}
  
      - name: Build C++11
-@@ -131,6 +144,7 @@
+@@ -130,6 +143,7 @@
          -DDOWNLOAD_CATCH=ON
          -DDOWNLOAD_EIGEN=ON
          -DCMAKE_CXX_STANDARD=17
@@ -34,7 +34,7 @@
          ${{ matrix.args }}
          ${{ matrix.args2 }}
  
-@@ -153,6 +167,7 @@
+@@ -152,6 +166,7 @@
          -DDOWNLOAD_CATCH=ON
          -DDOWNLOAD_EIGEN=ON
          -DCMAKE_CXX_STANDARD=17
@@ -42,7 +42,7 @@
          -DPYBIND11_INTERNALS_VERSION=10000000
          "-DPYBIND11_TEST_OVERRIDE=test_call_policies.cpp;test_gil_scoped.cpp;test_thread.cpp"
          ${{ matrix.args }}
-@@ -251,6 +266,7 @@
+@@ -252,6 +267,7 @@
          -DDOWNLOAD_CATCH=ON
          -DDOWNLOAD_EIGEN=ON
          -DCMAKE_CXX_STANDARD=17
@@ -50,7 +50,7 @@
  
      - name: Build
        run: cmake --build build -j 2
-@@ -305,6 +321,7 @@
+@@ -306,6 +322,7 @@
          -DPYBIND11_WERROR=ON
          -DDOWNLOAD_CATCH=ON
          -DCMAKE_CXX_STANDARD=${{ matrix.std }}
@@ -58,7 +58,7 @@
          -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
  
      - name: Build
-@@ -334,7 +351,8 @@
+@@ -335,7 +352,8 @@
        run: apt-get update && DEBIAN_FRONTEND="noninteractive" apt-get install -y cmake git python3-dev python3-pytest python3-numpy
  
      - name: Configure
@@ -68,7 +68,7 @@
  
      - name: Build
        run: cmake --build build -j2 --verbose
-@@ -414,7 +432,7 @@
+@@ -415,7 +433,7 @@
          cmake3 -S . -B build -DDOWNLOAD_CATCH=ON \
                              -DCMAKE_CXX_STANDARD=11 \
                              -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)") \
@@ -77,7 +77,7 @@
                              -DPYBIND11_TEST_FILTER="test_smart_ptr.cpp;test_virtual_functions.cpp"
  
      # Building before installing Pip should produce a warning but not an error
-@@ -473,6 +491,7 @@
+@@ -474,6 +492,7 @@
          -DPYBIND11_WERROR=ON
          -DDOWNLOAD_CATCH=ON
          -DCMAKE_CXX_STANDARD=${{ matrix.std }}
@@ -85,7 +85,7 @@
          -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
  
      - name: Build
-@@ -528,6 +547,7 @@
+@@ -529,6 +548,7 @@
          -DDOWNLOAD_CATCH=ON     \
          -DDOWNLOAD_EIGEN=OFF    \
          -DCMAKE_CXX_STANDARD=11             \
@@ -93,7 +93,7 @@
          -DCMAKE_CXX_COMPILER=$(which icpc)  \
          -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
  
-@@ -560,6 +580,7 @@
+@@ -561,6 +581,7 @@
          -DDOWNLOAD_CATCH=ON     \
          -DDOWNLOAD_EIGEN=OFF    \
          -DCMAKE_CXX_STANDARD=17             \
@@ -101,7 +101,7 @@
          -DCMAKE_CXX_COMPILER=$(which icpc)  \
          -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
  
-@@ -631,6 +652,7 @@
+@@ -633,6 +654,7 @@
          -DDOWNLOAD_CATCH=ON
          -DDOWNLOAD_EIGEN=ON
          -DCMAKE_CXX_STANDARD=11
@@ -109,7 +109,7 @@
          -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
  
      - name: Build
-@@ -681,6 +703,7 @@
+@@ -683,6 +705,7 @@
          cmake ../pybind11-tests
          -DDOWNLOAD_CATCH=ON
          -DPYBIND11_WERROR=ON
@@ -117,7 +117,7 @@
          -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
        working-directory: /build-tests
  
-@@ -776,6 +799,7 @@
+@@ -778,6 +801,7 @@
          -DPYBIND11_WERROR=ON
          -DDOWNLOAD_CATCH=ON
          -DDOWNLOAD_EIGEN=ON
@@ -125,7 +125,7 @@
          ${{ matrix.args }}
      - name: Build C++11
        run: cmake --build build -j 2
-@@ -822,6 +846,7 @@
+@@ -825,6 +849,7 @@
          -DPYBIND11_WERROR=ON
          -DDOWNLOAD_CATCH=ON
          -DDOWNLOAD_EIGEN=ON
@@ -133,22 +133,21 @@
  
      - name: Build C++14
        run: cmake --build build -j 2
-@@ -842,12 +867,13 @@
-           - 3.7
-         std:
-           - 14
-+        args: [ -DCMAKE_CXX_FLAGS="/GR /EHsc /DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT" ]
- 
-         include:
+@@ -850,11 +875,11 @@
            - python: 2.7
              std: 17
              args: >
 -              -DCMAKE_CXX_FLAGS="/permissive- /EHsc /GR"
++              -DCMAKE_CXX_FLAGS="/permissive- /EHsc /GR /DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT"
+           - python: 3.7
+             std: 17
+             args: >
+-              -DCMAKE_CXX_FLAGS="/permissive- /EHsc /GR"
 +              -DCMAKE_CXX_FLAGS="/permissive- /EHsc /GR /DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT"
  
      steps:
      - uses: actions/checkout@v2
-@@ -914,7 +940,7 @@
+@@ -923,7 +948,7 @@
      - name: Configure C++11
        # LTO leads to many undefined reference like
        # `pybind11::detail::function_call::function_call(pybind11::detail::function_call&&)
@@ -157,7 +156,7 @@
  
      - name: Build C++11
        run: cmake --build build -j 2
-@@ -932,7 +958,7 @@
+@@ -941,7 +966,7 @@
        run: git clean -fdx
  
      - name: Configure C++14
@@ -166,7 +165,7 @@
  
      - name: Build C++14
        run: cmake --build build2 -j 2
-@@ -950,7 +976,7 @@
+@@ -959,7 +984,7 @@
        run: git clean -fdx
  
      - name: Configure C++17