I have followed the sakai development walkthrough and it seems like the pom file for kernel 1.2.8 is missing due to which the email template service module does not build. This happened after i checked out from svn, sakai-trunk-all branch and then ran the mvn command from the email template service folder as indicated below.

~/opt/sakai-src-trunk/emailtemplateservice $ mvn -Pcafe clean install
[INFO] Scanning for projects...
[WARNING]
Profile with id: 'cafe' has not been activated.

[INFO] Reactor build order:
[INFO] Sakai Emailtemplateservice Base POM (emailtemplateservice)
[INFO] Sakai Emailtemplateservice API (emailtemplateservice-api)
[INFO] Sakai emailtemplateservice Deploy POM
[INFO] Sakai emailtemplateservice Shared Deploy
[INFO] Sakai Emailtemplateservice Implementation (emailtemplateservice-impl)
[INFO] Sakai Emailtemplateservice Components Package (emailtemplateservice-pack)
[INFO] Sakai Emailtemplateservice Tool (emailtemplateservice-tool)
[INFO] ------------------------------------------------------------------------
[INFO] Building Sakai Emailtemplateservice Base POM (emailtemplateservice)
[INFO] task-segment: [clean, install]
[INFO] ------------------------------------------------------------------------
[INFO] [clean:clean {execution: default-clean}]
[INFO] [enforcer:enforce {execution: enforce-maven}]
[INFO] [enforcer:enforce {execution: enforce-versions}]
[INFO] [site:attach-descriptor {execution: default-attach-descriptor}]
[INFO] [install:install {execution: default-install}]
[INFO] Installing /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/pom.xml to /home/mahadevan/.m2/repository/org/sakaiproject/emailtemplateservice/emailtemplateservice/2.10-SNAPSHOT/emailtemplateservice-2.10-SNAPSHOT.pom
[INFO] ------------------------------------------------------------------------
[INFO] Building Sakai Emailtemplateservice API (emailtemplateservice-api)
[INFO] task-segment: [clean, install]
[INFO] ------------------------------------------------------------------------
[INFO] [clean:clean {execution: default-clean}]
[INFO] Deleting directory /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/api/target
[INFO] [enforcer:enforce {execution: enforce-maven}]
[INFO] [enforcer:enforce {execution: enforce-versions}]
[INFO] [resources:resources {execution: default-resources}]
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] [compiler:compile {execution: default-compile}]
[INFO] Compiling 6 source files to /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/api/target/classes
[INFO] [resources:testResources {execution: default-testResources}]
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/api/src/test/java
[INFO] skip non existing resourceDirectory /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/api/src/test/resources
[INFO] [compiler:testCompile {execution: default-testCompile}]
[INFO] No sources to compile
[INFO] [surefire:test {execution: default-test}]
[INFO] No tests to run.
[INFO] Surefire report directory: /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/api/target/surefire-reports

-------------------------------------------------------
T E S T S
-------------------------------------------------------
There are no tests to run.

Results :

Tests run: 0, Failures: 0, Errors: 0, Skipped: 0

[INFO] [jar:jar {execution: default-jar}]
[INFO] Building jar: /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/api/target/emailtemplateservice-api-2.10-SNAPSHOT.jar
[INFO] [install:install {execution: default-install}]
[INFO] Installing /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/api/target/emailtemplateservice-api-2.10-SNAPSHOT.jar to /home/mahadevan/.m2/repository/org/sakaiproject/emailtemplateservice/emailtemplateservice-api/2.10-SNAPSHOT/emailtemplateservice-api-2.10-SNAPSHOT.jar
[INFO] ------------------------------------------------------------------------
[INFO] Building Sakai emailtemplateservice Deploy POM
[INFO] task-segment: [clean, install]
[INFO] ------------------------------------------------------------------------
[INFO] [clean:clean {execution: default-clean}]
[INFO] [enforcer:enforce {execution: enforce-maven}]
[INFO] [enforcer:enforce {execution: enforce-versions}]
[INFO] [site:attach-descriptor {execution: default-attach-descriptor}]
[INFO] [install:install {execution: default-install}]
[INFO] Installing /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/deploy/pom.xml to /home/mahadevan/.m2/repository/org/sakaiproject/emailtemplateservice/emailtemplateservice-deploy/2.10-SNAPSHOT/emailtemplateservice-deploy-2.10-SNAPSHOT.pom
[INFO] ------------------------------------------------------------------------
[INFO] Building Sakai emailtemplateservice Shared Deploy
[INFO] task-segment: [clean, install]
[INFO] ------------------------------------------------------------------------
[INFO] [clean:clean {execution: default-clean}]
[INFO] [enforcer:enforce {execution: enforce-maven}]
[INFO] [enforcer:enforce {execution: enforce-versions}]
[INFO] [site:attach-descriptor {execution: default-attach-descriptor}]
[INFO] [install:install {execution: default-install}]
[INFO] Installing /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/deploy/shared/pom.xml to /home/mahadevan/.m2/repository/org/sakaiproject/emailtemplateservice/emailtemplateservice-shared/2.10-SNAPSHOT/emailtemplateservice-shared-2.10-SNAPSHOT.pom
[INFO] ------------------------------------------------------------------------
[INFO] Building Sakai Emailtemplateservice Implementation (emailtemplateservice-impl)
[INFO] task-segment: [clean, install]
[INFO] ------------------------------------------------------------------------
[INFO] [clean:clean {execution: default-clean}]
[INFO] Deleting directory /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/impl/logic/target
[INFO] snapshot org.sakaiproject.entitybroker:entitybroker-api:2.10-SNAPSHOT: checking for updates from sakai-maven2-snapshots
[INFO] snapshot org.sakaiproject.entitybroker:entitybroker-api:2.10-SNAPSHOT: checking for updates from sonatype-nexus-snapshots
[WARNING] repository metadata for: 'snapshot org.sakaiproject.entitybroker:entitybroker-api:2.10-SNAPSHOT' could not be retrieved from repository: sonatype-nexus-snapshots due to an error: Error transferring file: Connection refused
[INFO] Repository 'sonatype-nexus-snapshots' will be blacklisted
[INFO] snapshot org.sakaiproject:entitybroker:2.10-SNAPSHOT: checking for updates from sakai-maven2-snapshots
[INFO] snapshot org.sakaiproject.kernel:sakai-kernel-api:2.10-SNAPSHOT: checking for updates from sakai-maven2-snapshots
[INFO] snapshot org.sakaiproject:kernel:2.10-SNAPSHOT: checking for updates from sakai-maven2-snapshots
[INFO] snapshot org.sakaiproject.kernel:sakai-component-manager:2.10-SNAPSHOT: checking for updates from sakai-maven2-snapshots
[INFO] [enforcer:enforce {execution: enforce-maven}]
[INFO] [enforcer:enforce {execution: enforce-versions}]
[INFO] [resources:resources {execution: default-resources}]
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO] Copying 0 resource
[INFO] [compiler:compile {execution: default-compile}]
[INFO] Compiling 5 source files to /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/impl/logic/target/classes
[INFO] [resources:testResources {execution: default-testResources}]
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 2 resources
[INFO] [compiler:testCompile {execution: default-testCompile}]
[INFO] Compiling 2 source files to /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/impl/logic/target/test-classes
[INFO] [surefire:test {execution: default-test}]
[INFO] Surefire report directory: /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/impl/logic/target/surefire-reports

-------------------------------------------------------
T E S T S
-------------------------------------------------------
Running org.sakaiproject.emailtemplateservice.logic.test.TestTextTemplateLogicUtils
log4j:WARN No appenders could be found for logger (freemarker.runtime).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.175 sec
testProcessTextTemplate(org.sakaiproject.emailtemplateservice.logic.test.TestTextTemplateLogicUtils) Time elapsed: 0.138 sec
Running org.sakaiproject.emailtemplateservice.logic.test.TestEmailTemplateService
Tests run: 4, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 1.049 sec
testGetEmailTemplate(org.sakaiproject.emailtemplateservice.logic.test.TestEmailTemplateService) Time elapsed: 0.976 sec
testSaveTemplate(org.sakaiproject.emailtemplateservice.logic.test.TestEmailTemplateService) Time elapsed: 0.019 sec
testGetTemplatebyId(org.sakaiproject.emailtemplateservice.logic.test.TestEmailTemplateService) Time elapsed: 0.01 sec
testEmptyTemplate(org.sakaiproject.emailtemplateservice.logic.test.TestEmailTemplateService) Time elapsed: 0.01 sec

Results :

Tests run: 5, Failures: 0, Errors: 0, Skipped: 0

[INFO] [jar:jar {execution: default-jar}]
[INFO] Building jar: /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/impl/logic/target/emailtemplateservice-impl-2.10-SNAPSHOT.jar
[INFO] [install:install {execution: default-install}]
[INFO] Installing /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/impl/logic/target/emailtemplateservice-impl-2.10-SNAPSHOT.jar to /home/mahadevan/.m2/repository/org/sakaiproject/emailtemplateservice/emailtemplateservice-impl/2.10-SNAPSHOT/emailtemplateservice-impl-2.10-SNAPSHOT.jar
[INFO] ------------------------------------------------------------------------
[INFO] Building Sakai Emailtemplateservice Components Package (emailtemplateservice-pack)
[INFO] task-segment: [clean, install]
[INFO] ------------------------------------------------------------------------
[INFO] [clean:clean {execution: default-clean}]
[INFO] Deleting directory /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/pack/target
[INFO] [enforcer:enforce {execution: enforce-maven}]
[INFO] [enforcer:enforce {execution: enforce-versions}]
[INFO] [resources:resources {execution: default-resources}]
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/pack/src/java
[INFO] skip non existing resourceDirectory /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/pack/src/bundle
[INFO] [compiler:compile {execution: default-compile}]
[INFO] No sources to compile
[INFO] [resources:testResources {execution: default-testResources}]
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/pack/src/test/java
[INFO] skip non existing resourceDirectory /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/pack/src/test/resources
[INFO] [compiler:testCompile {execution: default-testCompile}]
[INFO] No sources to compile
[INFO] [surefire:test {execution: default-test}]
[INFO] No tests to run.
[INFO] Surefire report directory: /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/pack/target/surefire-reports

-------------------------------------------------------
T E S T S
-------------------------------------------------------
There are no tests to run.

Results :

Tests run: 0, Failures: 0, Errors: 0, Skipped: 0

[INFO] [sakai:component {execution: default-component}]
[INFO] Exploding webapp...
[INFO] Assembling webapp emailtemplateservice-pack in /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/pack/target/emailtemplateservice-pack-2.10-SNAPSHOT
[INFO] Copy webapp webResources to /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/pack/target/emailtemplateservice-pack-2.10-SNAPSHOT
[INFO] Generating component /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/pack/target/emailtemplateservice-pack-2.10-SNAPSHOT.war
[INFO] Building war: /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/pack/target/emailtemplateservice-pack-2.10-SNAPSHOT.war
[INFO] [install:install {execution: default-install}]
[INFO] Installing /home/mahadevan/opt/sakai-src-trunk/emailtemplateservice/pack/target/emailtemplateservice-pack-2.10-SNAPSHOT.war to /home/mahadevan/.m2/repository/org/sakaiproject/emailtemplateservice/emailtemplateservice-pack/2.10-SNAPSHOT/emailtemplateservice-pack-2.10-SNAPSHOT.war
[INFO] ------------------------------------------------------------------------
[INFO] Building Sakai Emailtemplateservice Tool (emailtemplateservice-tool)
[INFO] task-segment: [clean, install]
[INFO] ------------------------------------------------------------------------
[INFO] [clean:clean {execution: default-clean}]
[INFO] snapshot uk.org.ponder.sakairsf:sakairsf:0.8.0-SNAPSHOT: checking for updates from sonatype-nexus-snapshots
[WARNING] repository metadata for: 'snapshot uk.org.ponder.sakairsf:sakairsf:0.8.0-SNAPSHOT' could not be retrieved from repository: sonatype-nexus-snapshots due to an error: Error transferring file: Connection refused
[INFO] Repository 'sonatype-nexus-snapshots' will be blacklisted
[INFO] snapshot uk.org.ponder.rsfutil:rsfutil:0.8.0-SNAPSHOT: checking for updates from Sakaiproject-Maven2
[WARNING] repository metadata for: 'snapshot uk.org.ponder.rsfutil:rsfutil:0.8.0-SNAPSHOT' could not be retrieved from repository: Sakaiproject-Maven2 due to an error: Error transferring file: Connection refused
[INFO] Repository 'Sakaiproject-Maven2' will be blacklisted
[INFO] snapshot uk.org.ponder:ponderutilcore:1.3.0-SNAPSHOT: checking for updates from sakai-maven2
[WARNING] repository metadata for: 'snapshot uk.org.ponder:ponderutilcore:1.3.0-SNAPSHOT' could not be retrieved from repository: sakai-maven2 due to an error: Error transferring file: Connection refused
[INFO] Repository 'sakai-maven2' will be blacklisted
[INFO] snapshot uk.org.ponder:ponderutilcore:1.3.0-SNAPSHOT: checking for updates from sakai-maven2-snaphsots
[WARNING] repository metadata for: 'snapshot uk.org.ponder:ponderutilcore:1.3.0-SNAPSHOT' could not be retrieved from repository: sakai-maven2-snaphsots due to an error: Error transferring file: Connection refused
[INFO] Repository 'sakai-maven2-snaphsots' will be blacklisted
Downloading: http://repo1.maven.org/maven2/org/sakaiproject/kernel/1.2.8/kernel-1.2.8.pom
[INFO] Unable to find resource 'org.sakaiproject:kernel:pom:1.2.8' in repository default (http://repo1.maven.org/maven2)
Downloading: http://repo1.maven.org/maven2/org/sakaiproject/kernel/1.2.8/kernel-1.2.8.pom
[INFO] Unable to find resource 'org.sakaiproject:kernel:pom:1.2.8' in repository central (http://repo1.maven.org/maven2)
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Error building POM (may not be this project's POM).

Project ID: org.sakaiproject:kernel

Reason: POM 'org.sakaiproject:kernel' not found in repository: Unable to download the artifact from any repository

org.sakaiproject:kernel:pom:1.2.8

from the specified remote repositories:
default (http://repo1.maven.org/maven2),
sakai-maven2-snapshots (http://source.sakaiproject.org/maven2-snapshots),
central (http://repo1.maven.org/maven2),
sakai-maven2-snaphsots (https://source.sakaiproject.org/maven2-snapshots),
sakai-maven2 (https://source.sakaiproject.org/maven2)

for project org.sakaiproject:kernel

[INFO] ------------------------------------------------------------------------
[INFO] For more information, run Maven with the -e switch
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 10 seconds
[INFO] Finished at: Thu Oct 17 14:04:50 IST 2013
[INFO] Final Memory: 52M/320M
[INFO] ------------------------------------------------------------------------