youknowdot · Oct 19, 2026 · Oct 19, 2026 · Oct 24, 2026 · Oct 24, 2026 · Oct 24, 2026
diff --git a/.cspell.dict/cpython.txt b/.cspell.dict/cpython.txt
@@ -211,6 +211,7 @@ prec
 preds
 preinitialized
 pybuilddir
+pycfunction
 pycore
 PYGC
 pyinner
@@ -311,3 +312,4 @@ xibufferview
 xstat
 XXPRIME
 ENOTCAPABLE
+unmarshalled
diff --git a/.cspell.dict/python-more.txt b/.cspell.dict/python-more.txt
@@ -306,3 +306,4 @@ xmlcharrefreplace
 xoptions
 xopts
 yieldfrom
+issubnormal
diff --git a/.cspell.dict/rustpython.txt b/.cspell.dict/rustpython.txt
@@ -40,3 +40,5 @@ rustix
 struc
 unscanned
 zelf
+embedders
+nocapture
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
@@ -581,30 +581,57 @@
 
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
 
+      - name: Verify the CPython reference environment
+        run: python -c "import bz2, ctypes, lzma, pathlib, platform, sqlite3, ssl; expected = pathlib.Path('.python-version').read_text().strip(); actual = platform.python_version(); assert actual == expected, (actual, expected)"
+
       - name: Install macOS dependencies
         uses: ./.github/actions/install-macos-deps
         with:
           openssl: true
 
-      # Keep features in sync with update-caches.yml CARGO_ARGS.
-      - name: build rustpython
-        run: cargo build --locked --release --verbose --features=threading,jit ${{ env.CARGO_ARGS }}
-
-      - name: run snippets
-        run: python -m pip install -r requirements.txt && pytest -v
-        working-directory: ./extra_tests
-
       - name: Detect available cores
         id: cores
         shell: bash
         run: |
           cores=$(python -c 'print(__import__("os").process_cpu_count())')
           echo "cores=${cores}" >> "$GITHUB_OUTPUT"
 
-      - name: Run CPython tests
+      - name: Build production RustPython
+        id: build_default
+        run: cargo build --locked --release --verbose --features=threading,jit ${{ env.CARGO_ARGS }}
+
+      - name: Record Windows timestamp compatibility
+        if: runner.os == 'Windows'
+        shell: bash
+        run: |
+          python - <<'PYTIME'
+          import json, subprocess, sys
+          code = """
+          import datetime, json, time
+          rows = []
+          for timestamp in (-1, -2147483649, -11644473600, -11644473601, 2**40):
+              for name in ('localtime', 'gmtime'):
+                  try:
+                      value = getattr(time, name)(timestamp)
+                      result = [list(value), value.tm_zone, value.tm_gmtoff]
+                  except Exception as error:
+                      result = [type(error).__name__, str(error), getattr(error, 'errno', None)]
+                  rows.append([timestamp, name, result])
+          print(json.dumps(rows))
+          """
+          for executable in (sys.executable, 'target/release/rustpython.exe'):
+              result = subprocess.check_output([executable, '-c', code], text=True)
+              print(json.dumps({'executable': executable, 'timestamps': json.loads(result)}))
+          PYTIME
+
+      - name: run snippets
+        run: python -m pip install -r requirements.txt && python -m pytest -v
+        working-directory: ./extra_tests
+
+      - name: Run CPython tests (production)
         run: |
           # shellcheck disable=SC2086
-          target/release/rustpython -u -m test --slow-ci -j "$CORES" $EXTRA_TEST_ARGS $SKIPS
+          target/release/rustpython -u -m test --slow-ci -j "$CORES" $EXTRA_TEST_ARGS $SKIPS -x test_frame test_inspect test_monitoring
         timeout-minutes: ${{ matrix.timeout }}
         shell: bash
         env:
@@ -677,6 +704,28 @@
         shell: bash
         run: python -I scripts/whats_left.py --rustpython target/release/rustpython
 
+      # Run all production checks before rebuilding the same binary with C API.
+      # Keep these features in sync with update-caches.yml CARGO_ARGS.
+      - name: Build RustPython with C API
+        id: build_capi
+        if: ${{ !cancelled() && steps.build_default.outcome == 'success' }}
+        run: cargo build --locked --release --verbose --features=threading,jit,capi ${{ env.CARGO_ARGS }}
+        env:
+          PYO3_CONFIG_FILE: ${{ github.workspace }}/crates/capi/pyo3-rustpython.config
+          PYO3_NO_PYTHON: "1"
+
+      # A failed production check must not suppress this cohort or become green.
+      - name: Run CPython tests (C API)
+        if: ${{ !cancelled() && steps.build_capi.outcome == 'success' }}
+        run: |
+          target/release/rustpython -u -m test --slow-ci -j "$CORES" $EXTRA_TEST_ARGS test_frame test_inspect test_monitoring
+        timeout-minutes: ${{ matrix.timeout }}
+        shell: bash
+        env:
+          RUSTPYTHON_SKIP_ENV_POLLUTERS: true
+          CORES: ${{ steps.cores.outputs.cores }}
+          EXTRA_TEST_ARGS: ${{ join(matrix.extra_test_args, ' ') }}
+
   clippy:
     # Named after the matrix entry rather than left to be named for it: a
     # generated name lists every value in the entry, so adding or removing one
@@ -731,7 +780,12 @@
         continue-on-error: true
 
       - name: Clippy
-        run: cargo clippy --locked --keep-going ${{ env.CARGO_ARGS_MOST_FEATS }} --workspace --all-targets --bins --examples --tests ${{ env.WORKSPACE_EXCLUDES }} -- -Dwarnings
+        run: cargo clippy --locked --keep-going ${{ env.CARGO_ARGS_MOST_FEATS }} --workspace --exclude rustpython-capi --all-targets --bins --examples --tests ${{ env.WORKSPACE_EXCLUDES }} -- -Dwarnings
+
+      # Load the C-API crate's RustPython-specific PyO3 configuration.
+      - name: Clippy C API
+        working-directory: crates/capi
+        run: cargo clippy --locked --all-targets -- -Dwarnings
 
   # macOS/Windows clippy uses the same OS-surface filter as cargo check.
   # Force with the run:cross-check label. Check names stay clippy (<os>).
@@ -794,6 +848,9 @@
 
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
 
+      - name: Verify the CPython reference environment
+        run: python -c "import bz2, ctypes, lzma, pathlib, platform, sqlite3, ssl; expected = pathlib.Path('.python-version').read_text().strip(); actual = platform.python_version(); assert actual == expected, (actual, expected)"
+
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: rustfmt
@@ -1061,10 +1118,13 @@
         builtin_str
         builtin_thread
         cli_int_max_str_digits
+        import_lazy_native
         protocol_index_argument
         recursion
         stdlib_ast
         stdlib_asyncio
+        stdlib_asyncio_reinitialization_315
+        stdlib_bytearray_take_bytes_threads_315
         stdlib_collections_deque
         stdlib_contextvars
         stdlib_ctypes
@@ -1076,17 +1136,20 @@
         stdlib_io_blocking_buffer
         stdlib_itertools
         stdlib_json
+        stdlib_lock_precedence_315
         stdlib_mmap
         stdlib_multiprocessing_condition
         stdlib_multiprocessing_fork_sharer
         stdlib_multiprocessing_sharedctypes
         stdlib_os
         stdlib_pwd
         stdlib_queue_signal
+        stdlib_rlock_constructor_315
         stdlib_select
         stdlib_socket
         stdlib_sqlite
         stdlib_ssl
+        stdlib_ssl_introspection
         stdlib_ssl_short_recv
         stdlib_struct
         stdlib_subinterpreters
@@ -1103,6 +1166,8 @@
         stdlib_types
         stdlib_typing
         stdlib_urllib_https_misaligned_recv
+        stdlib_venv_cycles
+        stdlib_weakref_gc_threads_315
         stdlib_zoneinfo_cache
         syntax_async
         syntax_async_comprehension

diff --git a/.github/workflows/cron-ci.yaml b/.github/workflows/cron-ci.yaml
@@ -17,6 +17,32 @@ env:
   CARGO_ARGS: --no-default-features --features stdlib,importlib,stdio,encodings,ssl-rustls-aws-lc,jit,host_env,doc,ucd_3_2_0
 
 jobs:
+  manager-coverage-regression:
+    name: Verify manager XML-RPC under coverage
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    # Leave room for the instrumented build and the normal 600-second test limit.
+    timeout-minutes: 30
+    if: ${{ github.repository == 'RustPython/RustPython' || github.event_name != 'schedule' }}
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+
+      - uses: dtolnay/rust-toolchain@stable
+
+      - uses: taiki-e/install-action@8cca0918f8471c33515202b73f56ab27f2bed283 # v2.87.29
+        with:
+          tool: cargo-llvm-cov
+
+      # Keep this strict check independent of the full coverage collection below.
+      - name: Run the canonical manager XML-RPC regression
+        run: >-
+          cargo llvm-cov --no-report run --locked --
+          -m test -v -u all --timeout 600 --match '*test_remote'
+          test_multiprocessing_forkserver.test_manager
+
   # codecov collects code coverage data from the rust tests, python snippets and python test suite.
   # This is done using cargo-llvm-cov, which is a wrapper around llvm-cov.
   codecov:
@@ -110,6 +136,9 @@ jobs:
 
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
 
+      - name: Verify the CPython reference environment
+        run: python -c "import bz2, ctypes, lzma, pathlib, platform, sqlite3, ssl; expected = pathlib.Path('.python-version').read_text().strip(); actual = platform.python_version(); assert actual == expected, (actual, expected)"
+
       - name: build rustpython
         run: cargo build --release --verbose --features sqlite
 
@@ -170,6 +199,12 @@ jobs:
 
       - uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
 
+      - name: Verify the CPython reference environment
+        run: python -c "import bz2, ctypes, lzma, pathlib, platform, sqlite3, ssl; expected = pathlib.Path('.python-version').read_text().strip(); actual = platform.python_version(); assert actual == expected, (actual, expected)"
+
+      - name: Make the reference libpython available to benchmark executables
+        run: echo "LD_LIBRARY_PATH=$(python -c 'import sysconfig; print(sysconfig.get_config_var("LIBDIR"))')${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}" >> "$GITHUB_ENV"
+
       - run: cargo install cargo-criterion
 
       - name: build benchmarks

diff --git a/.github/workflows/lib-deps-check.yaml b/.github/workflows/lib-deps-check.yaml
@@ -111,43 +111,80 @@ jobs:
 
       - name: Run deps check
         if: steps.changed-files.outputs.modules != ''
-        id: deps-check
         run: |
           # Run deps for all modules at once
-          echo "deps_output<<EOF" >> "$GITHUB_OUTPUT"
-          output=$(python scripts/update_lib deps "${MODULES}"  --depth 2 2>&1 || true)
-          output=$(python -c '
-          import sys
-
-          output = sys.stdin.read()
-          limit = 60000
-          encoded = output.encode()
-          if len(encoded) > limit:
-              output = encoded[:limit].decode("utf-8", errors="ignore")
-              output += "\n\n[Dependency report truncated to fit in a GitHub comment.]"
-          print(output, end="")
-          ' <<< "$output")
-          echo "$output" >> "$GITHUB_OUTPUT"
-          echo "EOF" >> "$GITHUB_OUTPUT"
+          python scripts/update_lib deps "${MODULES}" --depth 2 > "$RUNNER_TEMP/lib-deps-report.md" 2>&1 || true
         env:
           MODULES: ${{ steps.changed-files.outputs.modules }}
 
+      - name: Prepare dependency report
+        if: steps.changed-files.outputs.modules != ''
+        id: deps-comment
+        shell: python
+        run: |
+          from os import environ
+          from pathlib import Path
+
+          report_path = Path(environ["RUNNER_TEMP"]) / "lib-deps-report.md"
+          report = report_path.read_text(encoding="utf-8")
+          if report:
+              heading = "## 📦 Library Dependencies\n\n"
+              body = (
+                  heading
+                  + "The following Lib/ modules were modified. Here are their dependencies:\n\n"
+                  + report
+                  + "\n\n**Legend:**\n"
+                  + "- `[+]` path exists in CPython\n"
+                  + "- `[x]` up-to-date, `[ ]` outdated\n"
+              )
+              report_path.write_text(body, encoding="utf-8")
+              body_size = len(body.encode("utf-8"))
+              run_url = (
+                  f"{environ['GITHUB_SERVER_URL']}/{environ['GITHUB_REPOSITORY']}"
+                  f"/actions/runs/{environ['GITHUB_RUN_ID']}"
+              )
+
+              # Job summaries have a 1 MiB limit; keep larger reports as artifacts.
+              needs_artifact = body_size > 1024 * 1024
+              summary = body
+              if needs_artifact:
+                  summary = (
+                      heading
+                      + "The dependency report exceeds the job summary limit. "
+                      + "Download the full report from this run's `lib-deps-report` artifact.\n"
+                  )
+              with open(environ["GITHUB_STEP_SUMMARY"], "a", encoding="utf-8") as fd:
+                  fd.write(summary)
+
+              # Leave room for the action's marker, counting UTF-8 bytes, not characters.
+              comment = body
+              if body_size >= 60000:
+                  comment = (
+                      heading
+                      + "The dependency report is too large for a pull request comment. "
+                      + f"[View the full report in the workflow run]({run_url}#summary).\n"
+                  )
+              comment_path = Path(environ["RUNNER_TEMP"]) / "lib-deps-comment.md"
+              comment_path.write_text(comment, encoding="utf-8")
+              with open(environ["GITHUB_OUTPUT"], "a", encoding="utf-8") as fd:
+                  fd.write("has_report=true\n")
+                  fd.write(f"needs_artifact={str(needs_artifact).lower()}\n")
+
+      - name: Upload oversized dependency report
+        if: steps.deps-comment.outputs.needs_artifact == 'true'
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: lib-deps-report
+          path: ${{ runner.temp }}/lib-deps-report.md
+          if-no-files-found: error
+
       - name: Post comment
-        if: steps.deps-check.outputs.deps_output != ''
+        if: steps.deps-comment.outputs.has_report == 'true'
         uses: marocchino/sticky-pull-request-comment@5770ad5eb8f42dd2c4f34da00c94c5381e49af88 # v3.0.5
         with:
           header: lib-deps-check
           number: ${{ github.event.pull_request.number }}
-          message: |
-            ## 📦 Library Dependencies
-
-            The following Lib/ modules were modified. Here are their dependencies:
-
-            ${{ steps.deps-check.outputs.deps_output }}
-
-            **Legend:**
-            - `[+]` path exists in CPython
-            - `[x]` up-to-date, `[ ]` outdated
+          path: ${{ runner.temp }}/lib-deps-comment.md
 
       - name: Remove comment if no Lib changes
         if: steps.changed-files.outputs.modules == ''

diff --git a/.github/workflows/update-caches.yml b/.github/workflows/update-caches.yml
@@ -14,13 +14,15 @@ concurrency:
     cancel-in-progress: false
 
 env:
+  PYO3_CONFIG_FILE: ${{ github.workspace }}/crates/capi/pyo3-rustpython.config
+  PYO3_NO_PYTHON: "1"
   CARGO_INCREMENTAL: 0
   CARGO_TERM_COLOR: always
   CARGO_PROFILE_TEST_DEBUG: 0
   CARGO_PROFILE_DEV_DEBUG: 0
   CARGO_PROFILE_RELEASE_DEBUG: 0
   # Keep feature list in sync with CI's release build in .github/workflows/ci.yaml.
-  CARGO_ARGS: --workspace --no-default-features --features stdlib,importlib,stdio,encodings,sqlite,ssl-rustls-aws-lc,host_env,threading,jit,doc --exclude rustpython_wasm --exclude rustpython-venvlauncher
+  CARGO_ARGS: --workspace --no-default-features --features stdlib,importlib,stdio,encodings,sqlite,ssl-rustls-aws-lc,host_env,threading,jit,capi,doc --exclude rustpython_wasm --exclude rustpython-venvlauncher
 
 jobs:
   build-caches: