unstable options help - ensure no duplicates

CHANGELOG.md

@@ -13,6 +13,9 @@
 - Estimate gas on pending block by default [#8627](https://github.com/hyperledger/besu/pull/8627)
 - Upgrade Gradle to 8.14 and related plugins [#8638](https://github.com/hyperledger/besu/pull/8638)
 
+### Bug fixes
+- Fix `besu -X` unstable options help [#8662](https://github.com/hyperledger/besu/pull/8662)
+
 ## 25.5.0
 ### Breaking Changes
 - Changes to gas estimation algorithm for `eth_estimateGas` and `eth_createAccessList` [#8478](https://github.com/hyperledger/besu/pull/8478) - if you require the previous behavior, specify `--estimate-gas-tolerance-ratio=0.0`

besu/src/main/java/org/hyperledger/besu/cli/UnstableOptionsSubCommand.java

@@ -82,6 +82,7 @@ private void printUnstableOptions(
     final CommandLine.Model.CommandSpec cs = CommandLine.Model.CommandSpec.create();
     commandSpec.options().stream()
         .filter(option -> option.hidden() && option.names()[0].startsWith("--X"))
+        .distinct()
         .forEach(option -> cs.addOption(option.toBuilder().hidden(false).build()));
 
     if (cs.options().size() > 0) {

besu/src/test/java/org/hyperledger/besu/cli/BesuCommandTest.java

@@ -256,6 +256,14 @@ public void callingVersionDisplayBesuInfoVersion() {
     assertThat(commandErrorOutput.toString(UTF_8)).isEmpty();
   }
 
+  @Test
+  public void callingUnstableSubCommandMustNotError() {
+    parseCommand("-X");
+    final String expectedOutputStart = "Unstable options";
+    assertThat(commandErrorOutput.toString(UTF_8)).isEmpty();
+    assertThat(commandOutput.toString(UTF_8)).startsWith(expectedOutputStart);
+  }
+
   // Testing default values
   @Test
   public void callingBesuCommandWithoutOptionsMustSyncWithDefaultValues() {