common/hooks/pre-pkg/06-verify-python-deps: add hook

compares rdeps and Python module metadata to find missing dependencies
for python packages. this uses virtual packages to map python canonical
package names to void packages.

common/hooks/pre-pkg/06-verify-python-deps.sh

@@ -0,0 +1,17 @@
+# vim: set ts=4 sw=4 et:
+#
+# This hook executes the following tasks:
+#	- Verifies python module dependencies from dist-info's METADATA and egg-info's PKG-INFO
+
+hook() {
+    local py3_bin="${XBPS_MASTERDIR}/usr/bin/python3"
+
+    if [ -z "$nopyprovides" ] && [ -d "${PKGDESTDIR}/${py3_sitelib}" ] && [ -x "${py3_bin}" ]; then
+            PYTHONPATH="${XBPS_MASTERDIR}/${py3_sitelib}-bootstrap" "${py3_bin}" \
+                "${XBPS_COMMONDIR}"/scripts/parse-py-metadata.py \
+                ${NOCOLORS:+-C} ${XBPS_STRICT:+-s} -S "${PKGDESTDIR}/${py3_sitelib}" -v "${pkgver}" \
+                depends -e "${python_extras}" \
+                -V <( $XBPS_QUERY_XCMD -R -p provides -s "py3:" ) -D "${PKGDESTDIR}/rdeps" \
+                || msg_error "$pkgver: failed to verify python module dependencies\n"
+    fi
+}