Liberty doesn't compile JSP

Question

I am currently migrating an app from Websphere 9 to Liberty. I have an issue which I don't know if it is a bug from Liberty or a configuration issue from my side. Server.xml:

<?xml version="1.0" encoding="UTF-8"?>
<server description="new server">
<!-- Enable features -->
    <featureManager>
        <feature>javaee-7.0</feature>
        <feature>jaxws-2.2</feature>

        <feature>appSecurity-2.0</feature>
        <feature>beanValidation-1.1</feature>
        <feature>cdi-1.2</feature>
        <feature>ejbLite-3.2</feature>
        <feature>el-3.0</feature>
        <feature>javaMail-1.5</feature>
        <feature>jdbc-4.1</feature>
        <feature>jndi-1.0</feature>
        <feature>jpa-2.1</feature>
        <feature>jsp-2.3</feature>
        <feature>jaspic-1.1</feature>
        <feature>localConnector-1.0</feature>
        <feature>servlet-3.1</feature>
        <feature>ejbRemote-3.2</feature>
        <feature>heritageAPIs-1.1</feature>
       
</featureManager>


    <logging messageFormat="console" messageSource="message,trace,accessLog,ffdc,audit" />
    <library id="sharedlib">
      <fileset dir="/liberty/usr/shared/lib/global" includes="*.jar" scanInterval="5s" />
    </library>

    <dataSource id="DefaultDataSource" jndiName="jdbc/postgres/PreferencesDb">
        <jdbcDriver libraryRef="PostgresLib"/>
        <properties.postgresql databaseName="dbname" user="dbuser" password="dbpassword"  serverName="host.docker.internal" portNumber="5433"/>
    </dataSource>

    <library id="PostgresLib">
        <file name="/liberty/usr/shared/lib/postgresql-42.7.1.jar"/>
    </library>

    <jspEngine keepGenerated ="true"/>

    <basicRegistry id="basic" realm="BasicRealm"> 
      <user name="wsadmin" password="wsadmin" />> 
    </basicRegistry>
    
    <!-- To allow access to this server from a remote client host="*" has been added to the following element -->
    <httpEndpoint id="defaultHttpEndpoint"
                  host="*"
                  httpPort="9080"
                  httpsPort="9445" />
     <iiopEndpoint id="defaultIiopEndpoint" iiopPort="2910">
        <iiopsOptions iiopsPort="9503" sslRef="defaultSSLConfig"/>
    </iiopEndpoint> 
    <!-- Automatically expand WAR files and EAR files -->
    <applicationManager autoExpand="true"/>

   <application type="ear" id="AServer" location="Aserver.ear" name="a-server" startAfterRef="a-bootstrap" >
    <classloader commonLibraryRef="sharedlib"/>
   </application>
   <application type="ear" id="a-bootstrap" location="/liberty/usr/shared/apps/a-bootstrap.ear" name="a-bootstrap">
    <classloader commonLibraryRef="sharedlib" />
   </application>

</server>

When I deploy my app (ear) and load a page handled by a JSP, I have a FileNotFoundException:

java.io.FileNotFoundException: /opt/ibm/wlp/output/[redacted]/workarea/org.eclipse.osgi/73/data/temp/default_node/SMF_WebContainer/[redacted]/[redacted]/jsp/_index.java (No such file or directory)
    at java.io.FileOutputStream.open(FileOutputStream.java:313)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:253)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:139)
    at com.ibm.ws.jsp.translator.visitor.generator.JavaFileWriter.<init>(JavaFileWriter.java:43)
    at com.ibm.ws.jsp.translator.visitor.generator.GenerateVisitor.createWriter(GenerateVisitor.java:72)
    at com.ibm.ws.jsp.translator.visitor.generator.GenerateJspVisitor.<init>(GenerateJspVisitor.java:59)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

The issue seems to be that "/jsp" (or any other subfolders) are not existing when new FileOutputStream() is instantiated. If I create manually the folders, it is working.

If I launch liberty in debug mode, the folders get created and the JSP are properly generated ! And if after that, I launch the server without debug, it is also working.

Thus, I analyzed the differences between debug mode and regular mode, why the debug mode is creating the folders. It is working in debug because of this OpenLibery class: AbstractJSPExtensionServletWrapper.java:331 :

                        if (translationRequired == false && options.isDebugEnabled()) {
                            translationRequired = (this.debugClassFile == false);

                            // defect 182990 begin
                            // in WDT, we need to re-translate the JSP on each server startup so the debugger can be invoked on a JSP file
                            if (!translationRequired && getTarget() == null){
                                translationRequired = true;
                            }
                            //defect 182990 end
                            // defect 272935 begin
                            if (translationRequired && jspResources.getGeneratedSourceFile().getParentFile().exists() == false){
                                boolean rc = jspResources.getGeneratedSourceFile().getParentFile().mkdirs();
                                if(com.ibm.ejs.ras.TraceComponent.isAnyTracingEnabled()&&logger.isLoggable(Level.FINEST)){
                                    logger.logp(Level.FINEST, CLASS_NAME, "_checkForTranslation", (rc?"Created":"Unable to create") +" directory for generated source file ["+jspResources.getGeneratedSourceFile().getParentFile() +"]");
                                }
                            }
                            // defect 272935 end
                        }

This code is executed only in debug mode and will mkdirs() the missing folder.

My question is, why is it for debug only, and what am I missing for the regular mode to generate those folders as well ?

Thanks