Manually copy the DLL to the wheel's root

Author: aborgna-q

.github/workflows/python-wheels.yml

@@ -210,6 +210,21 @@ jobs:
             echo
           done
 
+      - name: Copy DLL to package directory (Windows)
+        if: runner.os == 'Windows'
+        shell: bash
+        run: |
+          # Copy the DLL to the package directory so maturin can include it in the wheel
+          # The maturin.include in pyproject.toml expects it relative to the package root
+          if [ -f "$TKET_C_API_PATH/bin/tket-c-api.dll" ]; then
+            cp "$TKET_C_API_PATH/bin/tket-c-api.dll" "$MODULE_DIR/tket-c-api.dll"
+            echo "Copied DLL to $MODULE_DIR/tket-c-api.dll"
+            ls -lh "$MODULE_DIR/tket-c-api.dll"
+          else
+            echo "ERROR: DLL not found at $TKET_C_API_PATH/bin/tket-c-api.dll"
+            exit 1
+          fi
+
       - name: Build wheels
         shell: bash
         run: |

tket-py/pyproject.toml

@@ -61,6 +61,13 @@ module-name = "tket._tket"
 manifest-path = "Cargo.toml"
 # "extension-module" tells pyo3 we want to build an extension module (skips linking against libpython.so)
 features = ["pyo3/extension-module"]
+include = [
+    # In windows targets, we need to explicitly include the DLL file if we want
+    # the wheel to be portable.
+    #
+    # This gets ignored when building for non-windows targets.
+    "tket-c-api.dll",
+]
 
 [tool.pytest.ini_options]
 # Lark throws deprecation warnings for `src_parse` and `src_constants`.