Eclipse Community Forums: TMF (Xtext) » Xtext 2.8.0 and Xtext Maven Plugin to generate the model artifacts

Home » Modeling » TMF (Xtext) » Xtext 2.8.0 and Xtext Maven Plugin to generate the model artifacts(Xtext 2.8.0 and Xtext Maven Plugin to generate the model artifacts)

Show: Today's Messages :: Show Polls :: Message Navigator

Xtext 2.8.0 and Xtext Maven Plugin to generate the model artifacts [message #1663523]

Tue, 10 March 2015 13:15

Adrian Pollak

Messages: 27
Registered: August 2013

Junior Member

Hello,

after todays automatic OSGI build update to Xtext 2.8.0 my maven build is not working any more.
The maven build that creates the DSL plugin (DSL+UI) works fine.
I have a problem, when I use the xtext-maven-plugin and try to generate the model artifacts (see the pom.xml extract).
My build throws the exception that can be found beneath.

Although the new libraries are received and stored in the maven repository in the p2 directory the xtend maven plugin (2.7.3) uses the libraries from C:\Applications\maven-repository_xy2\org\eclipse\xtext\org.eclipse.xtext.xbase\2.7.3 that do not have the needed class "org.eclipse.xtext.xbase.DefaultXbaseRuntimeModule".

Under http://mvnrepository.com/artifact/org.eclipse.xtend/xtend-maven-plugin there is no Xtend Maven Plugin of version 2.8.0.

Is there a way (workaround) to fix the build problem.

pom.xml:

...
<plugin>
	<groupId>org.eclipse.xtext</groupId>
	<artifactId>xtext-maven-plugin</artifactId>
	<version>2.7.3</version>

	<executions>
		<execution>
			<id>generate-model-artifacts</id>
			<phase>generate-sources</phase>
			<goals>
				<goal>generate</goal>
			</goals>
		</execution>
	</executions>
	
	<configuration>
		<compilerSourceLevel>${compilerSourceLevel.version}</compilerSourceLevel>
		<compilerTargetLevel>${compilerTargetLevel.version}</compilerTargetLevel>

		<languages>
			<language>
				<setup>com.my.dsl.RamDslStandaloneSetup</setup>
				<outputConfigurations>
					<outputConfiguration>
						<outputDirectory>../com.my.ram/src-gen/</outputDirectory>
						<createOutputDirectory>true</createOutputDirectory>
						<overrideExistingResources>true</overrideExistingResources>
						<cleanUpDerivedResources>true</cleanUpDerivedResources>
					</outputConfiguration>
				</outputConfigurations>
			</language>
		</languages>
	</configuration>

	<dependencies>
		<dependency>
			<groupId>com.my</groupId>
			<artifactId>com.my.dsl</artifactId>
			<version>1.0.0</version>
		</dependency>
		
		<dependency>
			<groupId>com.my</groupId>
			<artifactId>com.my.interfaces</artifactId>
			<version>1.0.0</version>
		</dependency>
	</dependencies>
</plugin>
...

Exception:

...
[INFO] ------------------------------------------------------------------------
[INFO] Building RAM Module 1.0.0
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.4.1:clean (default-clean) @ com.my.ram ---
[INFO]
[INFO] --- tycho-packaging-plugin:0.22.0:build-qualifier (default-build-qualifier) @ com.my.ram ---
[INFO] The project's OSGi version is 1.0.0
[INFO]
[INFO] --- tycho-packaging-plugin:0.22.0:validate-id (default-validate-id) @ com.my.ram ---
[INFO]
[INFO] --- tycho-packaging-plugin:0.22.0:validate-version (default-validate-version) @ com.my.ram ---
[INFO]
[INFO] --- build-helper-maven-plugin:1.8:add-source (add-source-xtext) @ com.my.ram ---
[INFO] Source directory: C:\workspaces\head\com.my.ram\target\target\xtext-temp added.
[INFO]
[INFO] --- xtext-maven-plugin:2.7.3:generate (generate-model-artifacts) @ com.my.ram ---
Downloading: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext.builder.standalone/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext.builder.standalone/maven-metadata.xml (732 B at 2.4 KB/sec)
Downloading: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext.xbase/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext.xbase/maven-metadata.xml (688 B at 3.0 KB/sec)
Downloading: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext/maven-metadata.xml (682 B at 3.2 KB/sec)
Downloading: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext.util/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext.util/maven-metadata.xml (439 B at 2.6 KB/sec)
Downloading: http://nexmach.net:8084/nexus/content/groups/public/com/google/guava/guava/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/com/google/guava/guava/maven-metadata.xml (2 KB at 8.8 KB/sec)
Downloading: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/emf/org.eclipse.emf.ecore/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/emf/org.eclipse.emf.ecore/maven-metadata.xml (794 B at 4.0 KB/sec)
Downloading: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/emf/org.eclipse.emf.common/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/emf/org.eclipse.emf.common/maven-metadata.xml (795 B at 3.6 KB/sec)
Downloading: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext.dependencies/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext.dependencies/maven-metadata.xml (695 B at 3.3 KB/sec)
Downloading: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext.xbase.lib/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext.xbase.lib/maven-metadata.xml (785 B at 4.0 KB/sec)
Downloading: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/emf/org.eclipse.emf.ecore.xmi/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/emf/org.eclipse.emf.ecore.xmi/maven-metadata.xml (798 B at 5.1 KB/sec)
Downloading: http://nexmach.net:8084/nexus/content/groups/public/org/antlr/antlr-runtime/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/org/antlr/antlr-runtime/maven-metadata.xml (900 B at 5.1 KB/sec)
Downloading: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtend/org.eclipse.xtend.lib/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtend/org.eclipse.xtend.lib/maven-metadata.xml (779 B at 5.6 KB/sec)
Downloading: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext.common.types/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext.common.types/maven-metadata.xml (695 B at 4.7 KB/sec)
Downloading: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/emf/org.eclipse.emf.codegen/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/emf/org.eclipse.emf.codegen/maven-metadata.xml (658 B at 4.1 KB/sec)
Downloading: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext.xtext/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/xtext/org.eclipse.xtext.xtext/maven-metadata.xml (688 B at 4.8 KB/sec)
Downloading: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/emf/org.eclipse.emf.codegen.ecore/maven-metadata.xml
Downloaded: http://nexmach.net:8084/nexus/content/groups/public/org/eclipse/emf/org.eclipse.emf.codegen.ecore/maven-metadata.xml (664 B at 4.2 KB/sec)
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 18.348s
[INFO] Finished at: Tue Mar 10 13:43:29 CET 2015
[INFO] Final Memory: 69M/308M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.eclipse.xtext:xtext-maven-plugin:2.7.3:generate (generate-model-artifacts) on project com.my.ram: Execution generate-model-artifacts of goal org.eclipse.xtext:xtext-maven-plugin:2.7.3:generate failed: A required class was missing while executing org.eclipse.xtext:xtext-maven-plugin:2.7.3:generate
: org/eclipse/xtext/xbase/DefaultXbaseRuntimeModule
[ERROR] -----------------------------------------------------
[ERROR] realm =    plugin>org.eclipse.xtext:xtext-maven-plugin:2.7.3
[ERROR] strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy
[ERROR] urls[0] = file:/C:/applications/maven-repository_xy2/org/eclipse/xtext/xtext-maven-plugin/2.7.3/xtext-maven-plugin-2.7.3.jar
[ERROR] urls[1] = file:/C:/applications/maven-repository_xy2/com/my/com.my.dsl/1.0.0/com.my.dsl-1.0.0.jar
[ERROR] urls[2] = file:/C:/applications/maven-repository_xy2/org/springframework/spring-beans/3.2.4.RELEASE/spring-beans-3.2.4.RELEASE.jar
[ERROR] urls[3] = file:/C:/applications/maven-repository_xy2/org/springframework/spring-core/3.2.4.RELEASE/spring-core-3.2.4.RELEASE.jar
[ERROR] urls[4] = file:/C:/applications/maven-repository_xy2/org/springframework/spring-context/3.2.4.RELEASE/spring-context-3.2.4.RELEASE.jar
[ERROR] urls[5] = file:/C:/applications/maven-repository_xy2/org/springframework/spring-aop/3.2.4.RELEASE/spring-aop-3.2.4.RELEASE.jar
[ERROR] urls[6] = file:/C:/applications/maven-repository_xy2/org/springframework/spring-expression/3.2.4.RELEASE/spring-expression-3.2.4.RELEASE.jar
[ERROR] urls[7] = file:/C:/applications/maven-repository_xy2/com/my/com.my.interfaces/1.0.0/com.my.interfaces-1.0.0.jar
[ERROR] urls[8] = file:/C:/applications/maven-repository_xy2/org/eclipse/aether/aether-spi/0.9.0.M2/aether-spi-0.9.0.M2.jar
[ERROR] urls[9] = file:/C:/applications/maven-repository_xy2/org/eclipse/aether/aether-impl/0.9.0.M2/aether-impl-0.9.0.M2.jar
[ERROR] urls[10] = file:/C:/applications/maven-repository_xy2/org/eclipse/aether/aether-api/0.9.0.M2/aether-api-0.9.0.M2.jar
[ERROR] urls[11] = file:/C:/applications/maven-repository_xy2/org/eclipse/aether/aether-util/0.9.0.M2/aether-util-0.9.0.M2.jar
[ERROR] urls[12] = file:/C:/applications/maven-repository_xy2/org/eclipse/sisu/org.eclipse.sisu.plexus/0.0.0.M5/org.eclipse.sisu.plexus-0.0.0.M5.jar
[ERROR] urls[13] = file:/C:/applications/maven-repository_xy2/javax/enterprise/cdi-api/1.0/cdi-api-1.0.jar
[ERROR] urls[14] = file:/C:/applications/maven-repository_xy2/javax/annotation/jsr250-api/1.0/jsr250-api-1.0.jar
[ERROR] urls[15] = file:/C:/applications/maven-repository_xy2/org/sonatype/sisu/sisu-guice/3.1.0/sisu-guice-3.1.0-no_aop.jar
[ERROR] urls[16] = file:/C:/applications/maven-repository_xy2/org/eclipse/sisu/org.eclipse.sisu.inject/0.0.0.M5/org.eclipse.sisu.inject-0.0.0.M5.jar
[ERROR] urls[17] = file:/C:/applications/maven-repository_xy2/org/codehaus/plexus/plexus-interpolation/1.19/plexus-interpolation-1.19.jar
[ERROR] urls[18] = file:/C:/applications/maven-repository_xy2/org/codehaus/plexus/plexus-utils/3.0.17/plexus-utils-3.0.17.jar
[ERROR] urls[19] = file:/C:/applications/maven-repository_xy2/org/codehaus/plexus/plexus-component-annotations/1.5.5/plexus-component-annotations-1.5.5.jar
[ERROR] urls[20] = file:/C:/applications/maven-repository_xy2/org/sonatype/plexus/plexus-sec-dispatcher/1.3/plexus-sec-dispatcher-1.3.jar
[ERROR] urls[21] = file:/C:/applications/maven-repository_xy2/org/sonatype/plexus/plexus-cipher/1.4/plexus-cipher-1.4.jar
[ERROR] urls[22] = file:/C:/applications/maven-repository_xy2/org/eclipse/xtext/org.eclipse.xtext.builder.standalone/2.7.3/org.eclipse.xtext.builder.standalone-2.7.3.jar
[ERROR] urls[23] = file:/C:/applications/maven-repository_xy2/org/eclipse/equinox/common/3.6.200-v20130402-1505/common-3.6.200-v20130402-1505.jar
[ERROR] urls[24] = file:/C:/applications/maven-repository_xy2/org/eclipse/xtext/org.eclipse.xtext.xbase/2.7.3/org.eclipse.xtext.xbase-2.7.3.jar
[ERROR] urls[25] = file:/C:/applications/maven-repository_xy2/org/eclipse/xtend/org.eclipse.xtend.lib/2.7.3/org.eclipse.xtend.lib-2.7.3.jar
[ERROR] urls[26] = file:/C:/applications/maven-repository_xy2/org/eclipse/xtend/org.eclipse.xtend.lib.macro/2.7.3/org.eclipse.xtend.lib.macro-2.7.3.jar
[ERROR] urls[27] = file:/C:/applications/maven-repository_xy2/org/eclipse/xtext/org.eclipse.xtext.xbase.lib/2.7.3/org.eclipse.xtext.xbase.lib-2.7.3.jar
[ERROR] urls[28] = file:/C:/applications/maven-repository_xy2/org/eclipse/xtext/org.eclipse.xtext/2.7.3/org.eclipse.xtext-2.7.3.jar
[ERROR] urls[29] = file:/C:/applications/maven-repository_xy2/org/eclipse/xtext/org.eclipse.xtext.dependencies/2.7.3/org.eclipse.xtext.dependencies-2.7.3.jar
[ERROR] urls[30] = file:/C:/applications/maven-repository_xy2/org/antlr/antlr-runtime/3.2/antlr-runtime-3.2.jar
[ERROR] urls[31] = file:/C:/applications/maven-repository_xy2/org/eclipse/emf/org.eclipse.emf.common/2.11.0-v20150123-0347/org.eclipse.emf.common-2.11.0-v20150123-0347.jar
[ERROR] urls[32] = file:/C:/applications/maven-repository_xy2/org/eclipse/emf/org.eclipse.emf.ecore/2.11.0-v20150123-0347/org.eclipse.emf.ecore-2.11.0-v20150123-0347.jar
[ERROR] urls[33] = file:/C:/applications/maven-repository_xy2/org/eclipse/emf/org.eclipse.emf.codegen/2.10.0-v20150123-0452/org.eclipse.emf.codegen-2.10.0-v20150123-0452.jar
[ERROR] urls[34] = file:/C:/applications/maven-repository_xy2/com/google/inject/guice/3.0/guice-3.0.jar
[ERROR] urls[35] = file:/C:/applications/maven-repository_xy2/javax/inject/javax.inject/1/javax.inject-1.jar
[ERROR] urls[36] = file:/C:/applications/maven-repository_xy2/aopalliance/aopalliance/1.0/aopalliance-1.0.jar
[ERROR] urls[37] = file:/C:/applications/maven-repository_xy2/com/google/guava/guava/14.0.1/guava-14.0.1.jar
[ERROR] urls[38] = file:/C:/applications/maven-repository_xy2/org/eclipse/xtext/org.eclipse.xtext.xtext/2.7.3/org.eclipse.xtext.xtext-2.7.3.jar
[ERROR] urls[39] = file:/C:/applications/maven-repository_xy2/org/eclipse/xtext/org.eclipse.xtext.util/2.7.3/org.eclipse.xtext.util-2.7.3.jar
[ERROR] urls[40] = file:/C:/applications/maven-repository_xy2/org/eclipse/xtext/org.eclipse.xtext.common.types/2.7.3/org.eclipse.xtext.common.types-2.7.3.jar
[ERROR] urls[41] = file:/C:/applications/maven-repository_xy2/org/ow2/asm/asm-commons/5.0.1/asm-commons-5.0.1.jar
[ERROR] urls[42] = file:/C:/applications/maven-repository_xy2/org/ow2/asm/asm-tree/5.0.1/asm-tree-5.0.1.jar
[ERROR] urls[43] = file:/C:/applications/maven-repository_xy2/org/ow2/asm/asm/5.0.1/asm-5.0.1.jar
[ERROR] urls[44] = file:/C:/applications/maven-repository_xy2/org/eclipse/emf/org.eclipse.emf.codegen.ecore/2.11.0-v20150123-0357/org.eclipse.emf.codegen.ecore-2.11.0-v20150123-0357.jar
[ERROR] urls[45] = file:/C:/applications/maven-repository_xy2/com/ibm/icu/icu4j/52.1/icu4j-52.1.jar
[ERROR] urls[46] = file:/C:/applications/maven-repository_xy2/commons-cli/commons-cli/1.2/commons-cli-1.2.jar
[ERROR] urls[47] = file:/C:/applications/maven-repository_xy2/commons-logging/commons-logging/1.1.3/commons-logging-1.1.3.jar
[ERROR] urls[48] = file:/C:/applications/maven-repository_xy2/org/eclipse/xtext/xtext-antlr-generator/2.1.1/xtext-antlr-generator-2.1.1.jar
[ERROR] urls[49] = file:/C:/applications/maven-repository_xy2/org/xtext/antlr-generator/3.2.1/antlr-generator-3.2.1.jar
[ERROR] urls[50] = file:/C:/applications/maven-repository_xy2/org/eclipse/emf/org.eclipse.emf.ecore.xmi/2.11.0-v20150123-0347/org.eclipse.emf.ecore.xmi-2.11.0-v20150123-0347.jar
[ERROR] urls[51] = file:/C:/applications/maven-repository_xy2/log4j/log4j/1.2.16/log4j-1.2.16.jar
[ERROR] Number of foreign imports: 1
[ERROR] import: Entry[import  from realm ClassRealm[project>com.my:com.my.ram:1.0.0, parent: ClassRealm[maven.api, parent: null]]]
[ERROR]
[ERROR] -----------------------------------------------------: org.eclipse.xtext.xbase.DefaultXbaseRuntimeModule
[ERROR] -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginContainerException
C:\workspaces\head\com.my.ram>

MANIFEST.MF

Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: Ram Models
Bundle-SymbolicName: com.my.ram
Bundle-Version: 1.0.0
Bundle-Vendor: My Company
Require-Bundle: com.my.interfaces;bundle-version="1.0.0",
 org.eclipse.xtext.xbase;bundle-version="2.8.0"
Bundle-RequiredExecutionEnvironment: JavaSE-1.6

Any help is appreciated.

Regards

Adrian

[Updated on: Wed, 11 March 2015 08:51]

Report message to a moderator

Re: Xtext 2.8.0 and Xtext Maven Plugin to generate the model artifacts [message #1663532 is a reply to message #1663523]

Tue, 10 March 2015 13:18

Christian Dietrich

Messages: 13887
Registered: July 2009

Senior Member

Hi,

what about setting bounds to the manifest [2.7.3,2.8.0) and wait with the update until the final release tomorrow?

Need professional support for Xtext, Xpand, EMF?
Go to: https://www.itemis.com/en/it-services/methods-and-tools/xtext
Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

Report message to a moderator

Re: Xtext 2.8.0 and Xtext Maven Plugin to generate the model artifacts [message #1663550 is a reply to message #1663532]

Tue, 10 March 2015 13:28

Adrian Pollak

Messages: 27
Registered: August 2013

Junior Member

Doing the change in the MANIFEST.MF file does not help.
I still get the same error.
Will there be tomorrow a new Xtend Maven Plugin for the version 2.8.0?

Report message to a moderator

Re: Xtext 2.8.0 and Xtext Maven Plugin to generate the model artifacts [message #1663601 is a reply to message #1663550]

Tue, 10 March 2015 14:00

Christian Dietrich

Messages: 13887
Registered: July 2009

Senior Member

i think so since the new release is planned for then.
are you sure you use maven to generated the xtext stuff as well?

Need professional support for Xtext, Xpand, EMF?
Go to: https://www.itemis.com/en/it-services/methods-and-tools/xtext
Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

Report message to a moderator

Re: Xtext 2.8.0 and Xtext Maven Plugin to generate the model artifacts [message #1663636 is a reply to message #1663601]

Tue, 10 March 2015 14:19

Adrian Pollak

Messages: 27
Registered: August 2013

Junior Member

Hello Christian,

my whole build is maven driven and everything was fine since the update.

By the way, who does the updates, maintenance for the Xtext libraries (p2) and who for the maven plugins and if there are different responsible companies are there any synchronization actions between them?

I deeply hope that the update will be done tomorrow.

Regards

Adrian

Report message to a moderator

Re: Xtext 2.8.0 and Xtext Maven Plugin to generate the model artifacts [message #1663697 is a reply to message #1663636]

Tue, 10 March 2015 14:54

Christian Dietrich

Messages: 13887
Registered: July 2009

Senior Member

HI,

have no idea why the p2 stuff is already there. but if you use strict versions the problem will never happen.
so there must still be something wrong with you setup,
else no xtext 2.8.0 stuff would be used

Need professional support for Xtext, Xpand, EMF?
Go to: https://www.itemis.com/en/it-services/methods-and-tools/xtext
Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

Report message to a moderator

Re: Xtext 2.8.0 and Xtext Maven Plugin to generate the model artifacts [message #1663750 is a reply to message #1663697]

Tue, 10 March 2015 15:25

Adrian Pollak

Messages: 27
Registered: August 2013

Junior Member

To use strict versions one has to set the versions for one library and all interdependend OSGI libraries within the manifest file.
But the dependency chain for the Xtext libraries is too long.
Otherwise the change of one library that is not fitted with a strict version leads to an error. I made that experience several times in the past.

In any case let me thank you for your help.
I hope that the xtend-maven-plugin (version 2.8.0) will be available tomorrow.

Regards

Adrian

Report message to a moderator