strip stack trace elements

wpilibNewCommands/src/main/java/edu/wpi/first/wpilibj2/command/CommandScheduler.java

@@ -23,6 +23,7 @@
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
@@ -637,18 +638,38 @@ public void requireNotComposed(Command... commands) {
     for (var command : commands) {
       var exception = m_composedCommands.getOrDefault(command, null);
       if (exception != null) {
+        exception.setStackTrace(stripFrameworkStackElements(exception.getStackTrace()));
         var buffer = new StringWriter();
         var writer = new PrintWriter(buffer);
         writer.println(
             "Commands that have been composed may not be added to another composition or scheduled "
                 + "individually!");
-        writer.println(exception.getMessage());
         exception.printStackTrace(writer);
-        throw new IllegalArgumentException(buffer.toString());
+        var thrownException = new IllegalArgumentException(buffer.toString());
+        thrownException.setStackTrace(stripFrameworkStackElements(thrownException.getStackTrace()));
+        throw thrownException;
       }
     }
   }
 
+  /**
+   * Strip all leading stack trace elements that are in the framework package.
+   *
+   * @param stacktrace the original stacktrace
+   * @return the stacktrace stripped of leading elements in the
+   *         edu.wpi.first.wpilibj2.command package.
+   */
+  private StackTraceElement[] stripFrameworkStackElements(StackTraceElement[] stacktrace) {
+    int i = 0;
+    for (; i < stacktrace.length; i++) {
+      if (stacktrace[0].getClassName().startsWith("edu.wpi.first.wpilibj2.command.")) {
+        continue;
+      }
+      break;
+    }
+    return Arrays.copyOfRange(stacktrace, i, stacktrace.length);
+  }
+
   /**
    * Requires that the specified commands have not already been added to a composition.
    *