fail license report job on missing licenses

Fixes #11554

ci/license_check.sh

@@ -3,5 +3,10 @@ export GRADLE_OPTS="-Dorg.gradle.daemon=false -Dorg.gradle.logging.level=info -D
 
 ./gradlew installDefaultGems
 bin/dependencies-report --csv report.csv
+
+result=$?
+
 # We want this to show on the CI server
 cat report.csv
+
+exit $result

logstash-core/lib/logstash/dependency_report.rb

@@ -32,8 +32,9 @@ class LogStash::DependencyReport < Clamp::Command
     command = ["./gradlew", "generateLicenseReport", "-PlicenseReportInputCSV=#{ruby_output_path}", "-PlicenseReportOutputCSV=#{output_path}"]
     puts "Executing #{command}"
     system(*command)
+
     if $?.exitstatus != 0
-      raise "Could not run gradle java deps! Exit status #{$?.exitstatus}"
+      raise "generateLicenseReport failed with exit status #{$?.exitstatus}"
     end
 
     nil

tools/dependencies-report/src/main/java/org/logstash/dependencies/Main.java

@@ -46,7 +46,7 @@ public class Main {
         );
 
         // If there were unknown results in the report, exit with a non-zero status
-        //System.exit(reportResult ? 0 : 1);
+        System.exit(reportResult ? 0 : 1);
     }
 
     static InputStream getResourceAsStream(String resourcePath) {