Invoking Maven for the goals: [org.apache.maven.plugins:maven-javadoc-plugin:2.7:javadoc] with no properties

M2_HOME=/usr/local/Cellar/maven/3.3.3/libexec
MAVEN_OPTS=  -Xmx512m
JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_60.jdk/Contents/Home/jre
JAVA_OPTS=null

[INFO] Scanning for projects...
[WARNING] 
[WARNING] Some problems were encountered while building the effective model for org.antlr:antlr4-tool-testsuite:jar:4.5.1
[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-surefire-plugin is missing. @ org.antlr:antlr4-tool-testsuite:[unknown-version], /Users/parrt/antlr/code/antlr4/target/checkout/tool-testsuite/pom.xml, line 76, column 15
[WARNING] 
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING] 
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
[WARNING] 
[INFO]                                                                         
[INFO] ------------------------------------------------------------------------
[INFO] Building ANTLR 4 Tool Tests 4.5.1
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] >>> maven-javadoc-plugin:2.7:javadoc (default-cli) > generate-sources @ antlr4-tool-testsuite >>>
[WARNING] The POM for org.antlr:antlr4-runtime:jar:4.5.1 is missing, no dependency information available
[WARNING] The POM for org.antlr:antlr4-runtime-testsuite:jar:4.5.1 is missing, no dependency information available
[WARNING] The POM for org.antlr:antlr4:jar:4.5.1 is missing, no dependency information available
[WARNING] The POM for org.antlr:antlr4:jar:tests:4.5.1 is missing, no dependency information available
[WARNING] The POM for org.antlr:antlr4-runtime-testsuite:jar:tests:4.5.1 is missing, no dependency information available
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.281 s
[INFO] Finished at: 2015-07-15T14:46:34-07:00
[INFO] Final Memory: 18M/491M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal on project antlr4-tool-testsuite: Could not resolve dependencies for project org.antlr:antlr4-tool-testsuite:jar:4.5.1: The following artifacts could not be resolved: org.antlr:antlr4-runtime:jar:4.5.1, org.antlr:antlr4-runtime-testsuite:jar:4.5.1, org.antlr:antlr4:jar:4.5.1, org.antlr:antlr4:jar:tests:4.5.1, org.antlr:antlr4-runtime-testsuite:jar:tests:4.5.1: Failure to find org.antlr:antlr4-runtime:jar:4.5.1 in https://repo.maven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced -> [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/DependencyResolutionException
