[rules score] add lobster rst report

bazel/rules/rules_score/private/dependable_element.bzl

@@ -790,6 +790,22 @@ def _dependable_element_index_impl(ctx):
     # Generate submodule links for the index page
     deps_links = _process_deps(ctx)
 
+    # The traceability report is generated into {label.name}/traceability_report/,
+    # which is a sibling of index.rst inside the same {label.name}/ srcdir that
+    # Sphinx uses (srcdir = parent of --index_file).  The toctree therefore
+    # references it as "traceability_report/index" with no "../" traversal.
+    # A lightweight provider-presence check mirrors the condition in the lobster
+    # block below; when no lobster inputs exist the substitution is empty so
+    # Sphinx does not complain about a missing document.
+    _has_feature_reqs = any([
+        FeatureRequirementsInfo in r or AssumedSystemRequirementsInfo in r
+        for r in ctx.attr.requirements
+    ])
+    _has_comp_reqs = any([ComponentInfo in c for c in ctx.attr.components])
+    traceability_report = (
+        "traceability_report/index" if _has_feature_reqs and _has_comp_reqs else ""
+    )
+
     # Render the index.rst using the template
     title = ctx.attr.module_name
     underline = "=" * len(title)
@@ -808,6 +824,7 @@ def _dependable_element_index_impl(ctx):
             "{dependability_analysis}": "\n   ".join(artifacts_by_type["dependability_analysis"]),
             "{checklists}": "\n   ".join(artifacts_by_type["checklists"]),
             "{submodules}": deps_links,
+            "{traceability_report}": traceability_report,
         },
     )
 
@@ -980,6 +997,7 @@ def _dependable_element_index_impl(ctx):
 
     lobster_report_file = None
     lobster_html_report = None
+    lobster_rst_dir = None
     lobster_files = []
     if feat_req_list and comp_req_list:
         lobster_config = ctx.actions.declare_file(ctx.label.name + "/de_traceability_config")
@@ -1002,7 +1020,28 @@ def _dependable_element_index_impl(ctx):
         lobster_report_file = subrule_lobster_report(all_lobster_inputs, lobster_config)
         lobster_html_report = subrule_lobster_html_report(lobster_report_file)
 
-        lobster_files = [lobster_config, lobster_report_file, lobster_html_report]
+        # Generate multi-page RST report inside the index subdirectory so that
+        # Sphinx (which uses {label.name}/index.rst's parent as srcdir) can
+        # resolve the toctree entry "traceability_report/index" without ../.
+        lobster_rst_dir = ctx.actions.declare_directory(
+            ctx.label.name + "/traceability_report",
+        )
+        package = ctx.label.package
+        package_depth = len(package.split("/")) if package else 0
+        source_root = "/".join([".." for _ in range(package_depth + 2)]) + "/"
+        rst_args = ctx.actions.args()
+        rst_args.add(lobster_report_file.path)
+        rst_args.add_all(["--out-dir", lobster_rst_dir.path])
+        rst_args.add_all(["--source-root", source_root])
+        ctx.actions.run(
+            executable = ctx.executable._lobster_rst_report,
+            inputs = [lobster_report_file],
+            outputs = [lobster_rst_dir],
+            arguments = [rst_args],
+            progress_message = "lobster-rst-report (pages) {}".format(ctx.label.name),
+        )
+
+        lobster_files = [lobster_config, lobster_report_file, lobster_html_report, lobster_rst_dir]
         output_files.extend(lobster_files)
 
     return [
@@ -1016,6 +1055,7 @@ def _dependable_element_index_impl(ctx):
         DependableElementLobsterInfo(
             lobster_report = lobster_report_file,
             lobster_html_report = lobster_html_report,
+            lobster_rst_dir = lobster_rst_dir,
         ),
         OutputGroupInfo(debug = depset([validation_log])),
     ]
@@ -1093,6 +1133,12 @@ _dependable_element_index = rule(
                 allow_single_file = True,
                 doc = "Lobster config template for dependable element traceability.",
             ),
+            "_lobster_rst_report": attr.label(
+                default = Label("//tools/lobster_rst_report:lobster-rst-report"),
+                executable = True,
+                cfg = "exec",
+                doc = "Lobster RST report tool for generating the multi-page Sphinx traceability report.",
+            ),
         },
         **VERBOSITY_ATTR
     ),

bazel/rules/rules_score/providers.bzl

@@ -205,6 +205,7 @@ DependableElementLobsterInfo = provider(
     fields = {
         "lobster_report": "The lobster report JSON File object, or None when no traceability data is available.",
         "lobster_html_report": "The lobster HTML report File object, or None when no traceability data is available.",
+        "lobster_rst_dir": "The lobster multi-page RST report TreeArtifact (directory), or None when no traceability data is available.",
     },
 )
 

bazel/rules/rules_score/templates/dependable_element_index.template.rst

@@ -61,6 +61,15 @@ Components
    {components}
 
 
+Traceability
+------------
+
+.. toctree::
+   :maxdepth: 1
+
+   {traceability_report}
+
+
 Checklists
 ----------
 

tools/lobster_rst_report/BUILD

@@ -0,0 +1,34 @@
+# *******************************************************************************
+# Copyright (c) 2026 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+
+load("@rules_python//python:defs.bzl", "py_binary", "py_library")
+
+py_library(
+    name = "lobster_rst_report_lib",
+    srcs = [
+        "__init__.py",
+        "_helpers.py",
+        "_renderers.py",
+        "graphviz_utils.py",
+        "rst_report.py",
+    ],
+    imports = [".."],
+    deps = ["@lobster//lobster/common"],
+)
+
+py_binary(
+    name = "lobster-rst-report",
+    srcs = ["lobster-rst-report.py"],
+    visibility = ["//visibility:public"],
+    deps = [":lobster_rst_report_lib"],
+)

tools/lobster_rst_report/__init__.py

@@ -0,0 +1,12 @@
+# *******************************************************************************
+# Copyright (c) 2026 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************