Merge in the main branch

Author: encukou

.github/workflows/jit.yml

@@ -35,6 +35,9 @@ jobs:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           persist-credentials: false
+      - name: Install dependencies
+        run: |
+          sudo ./.github/workflows/posix-deps-apt.sh
       - name: Build tier two interpreter
         run: |
           ./configure --enable-experimental-jit=interpreter --with-pydebug
@@ -152,6 +155,9 @@ jobs:
       - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
         with:
           python-version: '3.11'
+      - name: Install dependencies
+        run: |
+          sudo ./.github/workflows/posix-deps-apt.sh
       - name: Build
         run: |
           sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ env.LLVM_VERSION }}
@@ -188,6 +194,9 @@ jobs:
       - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
         with:
           python-version: '3.11'
+      - name: Install dependencies
+        run: |
+          sudo ./.github/workflows/posix-deps-apt.sh
       - name: Build
         run: |
           sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ env.LLVM_VERSION }}

.github/workflows/mypy.yml

@@ -71,7 +71,8 @@ jobs:
           persist-credentials: false
       - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
         with:
-          python-version: "3.13"
+          python-version: "3.15"
+          allow-prereleases: true
           cache: pip
           cache-dependency-path: Tools/requirements-dev.txt
       - run: pip install -r Tools/requirements-dev.txt

.readthedocs.yml

@@ -12,23 +12,47 @@ build:
   tools:
     python: "3"
 
-  commands:
-    # https://docs.readthedocs.io/en/stable/build-customization.html#cancel-build-based-on-a-condition
-    #
-    # Cancel building pull requests when there aren't changes in the Doc directory.
-    #
-    # If there are no changes (git diff exits with 0) we force the command to return with 183.
-    # This is a special exit code on Read the Docs that will cancel the build immediately.
-    - |
-      if [ "$READTHEDOCS_VERSION_TYPE" = "external" ] && [ "$(git diff --quiet origin/main -- Doc/ .readthedocs.yml; echo $?)" -eq 0 ];
-      then
-        echo "No changes to Doc/ - exiting the build.";
-        exit 183;
-      fi
-
-    - asdf plugin add uv
-    - asdf install uv latest
-    - asdf global uv latest
-    - make -C Doc venv html
-    - mkdir _readthedocs
-    - mv Doc/build/html _readthedocs/html
+  jobs:
+    post_checkout:
+      # https://docs.readthedocs.com/platform/stable/guides/build/skip-build.html#skip-builds-based-on-conditions
+      #
+      # Cancel building pull requests when there aren't changes in the Doc
+      # directory or RTD configuration, or if we can't cleanly merge the base
+      # branch.
+      - |
+        set -eEux;
+        if [ "$READTHEDOCS_VERSION_TYPE" = "external" ];
+        then
+          base_branch=main;
+          git fetch --depth=50 origin $base_branch:origin-$base_branch;
+          for attempt in $(seq 10);
+          do
+            if ! git merge-base HEAD origin-$base_branch;
+            then
+              git fetch --deepen=50 origin $base_branch;
+            else
+              break;
+            fi;
+          done;
+          if ! git -c "user.name=rtd" -c "user.email=no-reply@readthedocs.org" merge --no-stat --no-edit origin-$base_branch;
+          then
+            echo "Unsuccessful merge with '$base_branch' branch, skipping the build";
+            exit 183;
+          fi;
+          if git diff --exit-code --stat origin-$base_branch -- Doc/ .readthedocs.yml;
+          then
+            echo "No changes to Doc/ - skipping the build.";
+            exit 183;
+          fi;
+        fi;
+    create_environment:
+      - echo "Skipping default environment creation"
+    install:
+      - asdf plugin add uv
+      - asdf install uv latest
+      - asdf global uv latest
+    build:
+      html:
+        - make -C Doc venv html
+        - mkdir -p "$READTHEDOCS_OUTPUT"
+        - mv Doc/build/html "$READTHEDOCS_OUTPUT/"

Doc/c-api/exceptions.rst

@@ -1348,3 +1348,67 @@ Tracebacks
 
    This function returns ``0`` on success, and returns ``-1`` with an
    exception set on failure.
+
+.. c:function:: const char* PyUnstable_DumpTraceback(int fd, PyThreadState *tstate)
+
+   Write a trace of the Python stack in *tstate* into the file *fd*.  The format
+   looks like::
+
+      Traceback (most recent call first):
+        File "xxx", line xxx in <xxx>
+        File "xxx", line xxx in <xxx>
+        ...
+        File "xxx", line xxx in <xxx>
+
+   This function is meant to debug situations such as segfaults, fatal errors,
+   and similar. The file and function names it outputs are encoded to ASCII with
+   backslashreplace and truncated to 500 characters. It writes only the first
+   100 frames; further frames are truncated with the line ``...``.
+
+   This function will return ``NULL`` on success, or an error message on error.
+
+   This function is intended for use in crash scenarios such as signal handlers
+   for SIGSEGV, where the interpreter may be in an inconsistent state. Given
+   that it reads interpreter data structures that may be partially modified, the
+   function might produce incomplete output or it may even crash itself.
+
+   The caller does not need to hold an :term:`attached thread state`, nor does
+   *tstate* need to be attached.
+
+   .. versionadded:: next
+
+.. c:function:: const char* PyUnstable_DumpTracebackThreads(int fd, PyInterpreterState *interp, PyThreadState *current_tstate, Py_ssize_t max_threads)
+
+   Write the traces of all Python threads in *interp* into the file *fd*.
+
+   If *interp* is ``NULL`` then this function will try to identify the current
+   interpreter using thread-specific storage. If it cannot, it will return an
+   error.
+
+   If *current_tstate* is not ``NULL`` then it will be used to identify what the
+   current thread is in the written output. If it is ``NULL`` then this function
+   will identify the current thread using thread-specific storage. It is not an
+   error if the function is unable to get the current Python thread state.
+
+   This function will return ``NULL`` on success, or an error message on error.
+
+   This function is meant to debug debug situations such as segfaults, fatal
+   errors, and similar. It calls :c:func:`PyUnstable_DumpTraceback` for each
+   thread. It only writes the tracebacks of the first *max_threads* threads,
+   further output is truncated with the line ``...``. If *max_threads* is 0, the
+   function will use a default value of 100 for the argument.
+
+   This function is intended for use in crash scenarios such as signal handlers
+   for SIGSEGV, where the interpreter may be in an inconsistent state. Given
+   that it reads interpreter data structures that may be partially modified, the
+   function might produce incomplete output or it may even crash itself.
+
+   The caller does not need to hold an :term:`attached thread state`, nor does
+   *current_tstate* need to be attached.
+
+   .. warning::
+      On the :term:`free-threaded build`, this function is not thread-safe. If
+      another thread deletes its :term:`thread state` while this function is being
+      called, the process will likely crash.
+
+   .. versionadded:: next