fix workflow issues

.github/workflows/rust-ci.yml

@@ -44,11 +44,8 @@ jobs:
         with:
           command: fmt
           args: --all -- --check
-      - name: Run doctest
-        uses: actions-rs/cargo@v1
-        with:
-          command: test
-          args: --workspace --doc
+      - name: Run doctests
+        run: ./tools/run_doctests.sh
       - name: Run cargo doc
         # This step is required to detect possible errors in docs that are not doctests.
         uses: actions-rs/cargo@v1

.github/workflows/security-audit.yml

@@ -56,8 +56,6 @@ jobs:
         uses: github/codeql-action/init@v2
         with:
           languages: ${{ matrix.language }}
-      - name: Build Digital Twins Connector
-        run: ./cloud_connectors/azure/digital_twins_connector/build.sh
       - name: Build MQTT Connector's Azure Function
         run: dotnet build cloud_connectors/azure/mqtt_connector/azure_function/src/function.csproj
       - name: Perform CodeQL Analysis

cloud_connectors/azure/mqtt_connector/README.md

@@ -12,7 +12,7 @@ The Azure MQTT Cloud Connector forwards data emitted by Freyja to an Azure Event
 
 ![Component Diagram](../../../docs/diagrams/azure_mqtt_cloud_connector.svg)
 
-Note that since this cloud connector interfaces with MQTT, it can be configured for use with any MQTT endpoint, not just the Azure-based solution shown here. The architecture diagram and the setup steps presented in this document provide a sample of a full end-to-end architecture that integrates this connector with a cloud digital twin solution.
+Note that since this cloud connector interfaces with MQTT, it can be configured for use with any MQTT endpoint, not only the Azure-based solution shown here. The architecture diagram and the setup steps presented in this document provide a sample of a full end-to-end architecture that integrates this connector with a cloud digital twin solution.
 
 ## Prerequisites
 

tools/run_doctests.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT license.
+# SPDX-License-Identifier: MIT
+
+# Running `cargo test --workspace --doc` will fail if the workspace contains only binary packages.
+# Normally doc tests are only supported for library packages and binary packages will be skipped,
+# but for some reason if a workspace contains only binary packages then the test command will fail.
+# This script runs the test command and suppresses the error caused in this case.
+# Unfortunately there are no tools to easily navigate a workspace and filter packages by type,
+# so this script works by checking the output of the test command.
+# Although this is not robust, it is far simpler than the alternative.
+OUTPUT=$(cargo test --workspace --doc 2>&1)
+RETURN_CODE=$?
+
+echo $OUTPUT
+echo
+
+if [[ $OUTPUT =~ "error: no library targets found in packages" ]]; then
+    echo "Detected 'no library targets' error, which is being suppressed"
+    exit 0
+else
+    exit $RETURN_CODE
+fi