CLI stack traces when debugging

pantheon/src/main/java/tech/pegasys/pantheon/Pantheon.java

@@ -13,7 +13,6 @@
 package tech.pegasys.pantheon;
 
 import static org.apache.logging.log4j.LogManager.getLogger;
-import static picocli.CommandLine.defaultExceptionHandler;
 
 import tech.pegasys.pantheon.cli.PantheonCommand;
 import tech.pegasys.pantheon.cli.PantheonControllerBuilder;
@@ -38,7 +37,7 @@ public static void main(final String... args) {
 
     pantheonCommand.parse(
         new RunLast().andExit(SUCCESS_EXIT_CODE),
-        defaultExceptionHandler().andExit(ERROR_EXIT_CODE),
+        pantheonCommand.exceptionHandler().andExit(ERROR_EXIT_CODE),
         System.in,
         args);
   }

pantheon/src/main/java/tech/pegasys/pantheon/cli/ConfigOptionSearchAndRunHandler.java

@@ -18,7 +18,6 @@
 
 import picocli.CommandLine;
 import picocli.CommandLine.AbstractParseResultHandler;
-import picocli.CommandLine.DefaultExceptionHandler;
 import picocli.CommandLine.ExecutionException;
 import picocli.CommandLine.Model.OptionSpec;
 import picocli.CommandLine.ParseResult;
@@ -27,13 +26,13 @@ class ConfigOptionSearchAndRunHandler extends AbstractParseResultHandler<List<Ob
   private static final String DOCKER_CONFIG_LOCATION = "/etc/pantheon/pantheon.conf";
 
   private final AbstractParseResultHandler<List<Object>> resultHandler;
-  private final DefaultExceptionHandler<List<Object>> exceptionHandler;
+  private final CommandLine.IExceptionHandler2<List<Object>> exceptionHandler;
   private final String configFileOptionName;
   private final boolean isDocker;
 
   ConfigOptionSearchAndRunHandler(
       final AbstractParseResultHandler<List<Object>> resultHandler,
-      final DefaultExceptionHandler<List<Object>> exceptionHandler,
+      final CommandLine.IExceptionHandler2<List<Object>> exceptionHandler,
       final String configFileOptionName,
       final boolean isDocker) {
     this.resultHandler = resultHandler;

pantheon/src/main/java/tech/pegasys/pantheon/cli/PantheonCommand.java

@@ -70,8 +70,10 @@
 import java.util.List;
 import java.util.Optional;
 import java.util.function.Function;
+import java.util.function.Supplier;
 import java.util.stream.Stream;
 
+import com.google.common.base.Suppliers;
 import com.google.common.io.Resources;
 import io.vertx.core.Vertx;
 import io.vertx.core.json.DecodeException;
@@ -82,7 +84,6 @@
 import picocli.CommandLine;
 import picocli.CommandLine.AbstractParseResultHandler;
 import picocli.CommandLine.Command;
-import picocli.CommandLine.DefaultExceptionHandler;
 import picocli.CommandLine.ExecutionException;
 import picocli.CommandLine.ITypeConverter;
 import picocli.CommandLine.Option;
@@ -458,6 +459,39 @@ private Long configureRefreshDelay(final Long refreshDelay) {
           "The address to which the privacy pre-compiled contract will be mapped to (default: ${DEFAULT-VALUE})")
   private final Integer privacyPrecompiledAddress = Address.PRIVACY;
 
+  // Inner class so we can get to loggingLevel.
+  public class PantheonExceptionHandler
+      extends CommandLine.AbstractHandler<List<Object>, PantheonExceptionHandler>
+      implements CommandLine.IExceptionHandler2<List<Object>> {
+
+    @Override
+    public List<Object> handleParseException(final ParameterException ex, final String[] args) {
+      if (logLevel != null && Level.DEBUG.isMoreSpecificThan(logLevel)) {
+        ex.printStackTrace(err());
+      } else {
+        err().println(ex.getMessage());
+      }
+      if (!CommandLine.UnmatchedArgumentException.printSuggestions(ex, err())) {
+        ex.getCommandLine().usage(err(), ansi());
+      }
+      return returnResultOrExit(null);
+    }
+
+    @Override
+    public List<Object> handleExecutionException(
+        final ExecutionException ex, final CommandLine.ParseResult parseResult) {
+      return throwOrExit(ex);
+    }
+
+    @Override
+    protected PantheonExceptionHandler self() {
+      return this;
+    }
+  }
+
+  private Supplier<PantheonExceptionHandler> exceptionHandlerSupplier =
+      Suppliers.memoize(PantheonExceptionHandler::new);
+
   public PantheonCommand(
       final Logger logger,
       final BlockImporter blockImporter,
@@ -475,7 +509,7 @@ public PantheonCommand(
 
   public void parse(
       final AbstractParseResultHandler<List<Object>> resultHandler,
-      final DefaultExceptionHandler<List<Object>> exceptionHandler,
+      final PantheonExceptionHandler exceptionHandler,
       final InputStream in,
       final String... args) {
 
@@ -578,7 +612,7 @@ public void run() {
           metricsConfiguration(),
           permissioningConfiguration);
     } catch (Exception e) {
-      throw new ParameterException(this.commandLine, e.getMessage());
+      throw new ParameterException(this.commandLine, e.getMessage(), e);
     }
   }
 
@@ -1028,4 +1062,8 @@ private boolean isFullInstantiation() {
   public MetricsSystem getMetricsSystem() {
     return metricsSystem;
   }
+
+  public PantheonExceptionHandler exceptionHandler() {
+    return exceptionHandlerSupplier.get();
+  }
 }

pantheon/src/test/java/tech/pegasys/pantheon/cli/CommandTestAbstract.java

@@ -36,7 +36,6 @@
 import java.net.URI;
 import java.nio.file.Path;
 import java.util.Collection;
-import java.util.List;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -51,7 +50,6 @@
 import org.mockito.Mockito;
 import org.mockito.junit.MockitoJUnitRunner;
 import picocli.CommandLine;
-import picocli.CommandLine.DefaultExceptionHandler;
 import picocli.CommandLine.Help.Ansi;
 import picocli.CommandLine.RunLast;
 
@@ -159,7 +157,7 @@ protected CommandLine.Model.CommandSpec parseCommand(final InputStream in, final
     // parse using Ansi.OFF to be able to assert on non formatted output results
     pantheonCommand.parse(
         new RunLast().useOut(outPrintStream).useAnsi(Ansi.OFF),
-        new DefaultExceptionHandler<List<Object>>().useErr(errPrintStream).useAnsi(Ansi.OFF),
+        pantheonCommand.exceptionHandler().useErr(errPrintStream).useAnsi(Ansi.OFF),
         in,
         args);
     return pantheonCommand.spec;