Two the same classes in maven dependencies. sealing violation - maven

Question

today I have bumped with an unusual situation..
For testing Java EE I am going to use glassfish-embedded-all.
In production I am going to use apache derby data base.
So when I wrote small test class for testing DB I got this error:
java.lang.SecurityException: sealing violation: can't seal package org.apache.derby.impl.services.locks: already loaded
My pom:
<dependencies>
<dependency>
<groupId>org.apache.derby</groupId>
<artifactId>derby</artifactId>
<version>10.14.2.0</version>
</dependency>
<dependency>
<groupId>org.apache.derby</groupId>
<artifactId>derbynet</artifactId>
<version>10.14.2.0</version>
</dependency>
<dependency>
<groupId>org.apache.derby</groupId>
<artifactId>derbyclient</artifactId>
<version>10.14.2.0</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.glassfish.main.extras</groupId>
<artifactId>glassfish-embedded-all</artifactId>
<version>3.1.2</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>6.0</version>
<scope>provided</scope>
</dependency>
</dependencies>
The problem is that embedded server also has derby classes.
So I have dervy classes for compile and I have derby classed for tests.
And during test It causes the conflict which I don't knwo how to solve.
Seems I need to ignore derиy classes in embedded server during test. Any ideas?
My tests:
public class JpaTest {
private static final String PERSISTENCE_UNIT_NAME = "people";
private EntityManagerFactory factory;
#Before
public void setUp() throws Exception {
factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
// Error appear here
EntityManager em = factory.createEntityManager();
P.S.
Ican't undersnat how Maven shade plugins work. Seems this plugin ia aimed for final jar. Not for unit test right now...
P.S.2.
If i try to execute test in some Main method it works fine (becase there is no glassfish dependency)

Answer 1

If i don't remember wrong, maven compile scope is used in every phase of the lifecicle, so dependencies with compile scope are used on test phase too. The solution claims to exclude the derby dependencies from glassfish one to force to use yours.
More on, you have dependencies with explicit scope defined as compile, and others than nothing is specified...theese are the same, as maven takes as default scope compile one