错误原因：

编译下载最新的maven源代码，但是出现错误。错误如下：

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-mapreduce-client-core:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-mapreduce-client-common:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-mapreduce-client-shuffle:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-mapreduce-client-app:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-mapreduce-client-jobclient:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-mapreduce-client-hs:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-mapreduce-client-hs-plugins:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-mapreduce-client:pom:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-mapreduce-examples:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-mapreduce:pom:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-streaming:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-distcp:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-archives:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-rumen:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-gridmix:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-datajoin:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-tools-dist:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-extras:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-pipes:pom:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-tools:pom:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-dist:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-client:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-minicluster:jar:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ org.apache.hadoop:hadoop-main:3.0.0-SNAPSHOT, E:\hadoo

p-common-trunk\pom.xml, line 278, column 15

[WARNING]

[WARNING] Some problems were encountered while building the effective model for

org.apache.hadoop:hadoop-main:pom:3.0.0-SNAPSHOT

[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-enfo

rcer-plugin is missing. @ line 278, column 15

[WARNING]

[WARNING] It is highly recommended to fix these problems because they threaten t

he stability of your build.

[WARNING]

[WARNING] For this reason, future Maven versions might no longer support buildin

g such malformed projects.

[WARNING]

[INFO] ------------------------------------------------------------------------

[INFO] Reactor Build Order:

[INFO]

[INFO] Apache Hadoop Main

[INFO] Apache Hadoop Project POM

[INFO] Apache Hadoop Annotations

[INFO] Apache Hadoop Project Dist POM

[INFO] Apache Hadoop Assemblies

[INFO] Apache Hadoop Maven Plugins

[INFO] Apache Hadoop MiniKDC

[INFO] Apache Hadoop Auth

[INFO] Apache Hadoop Auth Examples

[INFO] Apache Hadoop Common

[INFO] Apache Hadoop NFS

[INFO] Apache Hadoop Common Project

[INFO] Apache Hadoop HDFS

[INFO] Apache Hadoop HttpFS

[INFO] Apache Hadoop HDFS BookKeeper Journal

[INFO] Apache Hadoop HDFS-NFS

[INFO] Apache Hadoop HDFS Project

[INFO] hadoop-yarn

[INFO] hadoop-yarn-api

[INFO] hadoop-yarn-common

[INFO] hadoop-yarn-server

[INFO] hadoop-yarn-server-common

[INFO] hadoop-yarn-server-nodemanager

[INFO] hadoop-yarn-server-web-proxy

[INFO] hadoop-yarn-server-resourcemanager

[INFO] hadoop-yarn-server-tests

[INFO] hadoop-yarn-client

[INFO] hadoop-yarn-applications

[INFO] hadoop-yarn-applications-distributedshell

[INFO] hadoop-mapreduce-client

[INFO] hadoop-mapreduce-client-core

[INFO] hadoop-yarn-applications-unmanaged-am-launcher

[INFO] hadoop-yarn-site

[INFO] hadoop-yarn-project

[INFO] hadoop-mapreduce-client-common

[INFO] hadoop-mapreduce-client-shuffle

[INFO] hadoop-mapreduce-client-app

[INFO] hadoop-mapreduce-client-hs

[INFO] hadoop-mapreduce-client-jobclient

[INFO] hadoop-mapreduce-client-hs-plugins

[INFO] Apache Hadoop MapReduce Examples

[INFO] hadoop-mapreduce

[INFO] Apache Hadoop MapReduce Streaming

[INFO] Apache Hadoop Distributed Copy

[INFO] Apache Hadoop Archives

[INFO] Apache Hadoop Rumen

[INFO] Apache Hadoop Gridmix

[INFO] Apache Hadoop Data Join

[INFO] Apache Hadoop Extras

[INFO] Apache Hadoop Pipes

[INFO] Apache Hadoop Tools Dist

[INFO] Apache Hadoop Tools

[INFO] Apache Hadoop Distribution

[INFO] Apache Hadoop Client

[INFO] Apache Hadoop Mini-Cluster

[INFO]

[INFO] ------------------------------------------------------------------------

[INFO] Building Apache Hadoop Main 3.0.0-SNAPSHOT

[INFO] ------------------------------------------------------------------------

Downloading: http://172.21.77.119:8081/nexus/content/groups/public/org/apache/ma

ven/plugins/maven-enforcer-plugin/maven-metadata.xml

Downloaded: http://172.21.77.119:8081/nexus/content/groups/public/org/apache/mav

en/plugins/maven-enforcer-plugin/maven-metadata.xml (714 B at 4.4 KB/sec)

[INFO]

[INFO] --- maven-enforcer-plugin:1.3.1:enforce (clean) @ hadoop-main ---

Downloading: http://172.21.77.119:8081/nexus/content/groups/public/commons-lang/

commons-lang/2.3/commons-lang-2.3.jar

[INFO] ------------------------------------------------------------------------

[INFO] Reactor Summary:

[INFO]

[INFO] Apache Hadoop Main ................................ FAILURE [0.531s]

[INFO] Apache Hadoop Project POM ......................... SKIPPED

[INFO] Apache Hadoop Annotations ......................... SKIPPED

[INFO] Apache Hadoop Project Dist POM .................... SKIPPED

[INFO] Apache Hadoop Assemblies .......................... SKIPPED

[INFO] Apache Hadoop Maven Plugins ....................... SKIPPED

[INFO] Apache Hadoop MiniKDC ............................. SKIPPED

[INFO] Apache Hadoop Auth ................................ SKIPPED

[INFO] Apache Hadoop Auth Examples ....................... SKIPPED

[INFO] Apache Hadoop Common .............................. SKIPPED

[INFO] Apache Hadoop NFS ................................. SKIPPED

[INFO] Apache Hadoop Common Project ...................... SKIPPED

[INFO] Apache Hadoop HDFS ................................ SKIPPED

[INFO] Apache Hadoop HttpFS .............................. SKIPPED

[INFO] Apache Hadoop HDFS BookKeeper Journal ............. SKIPPED

[INFO] Apache Hadoop HDFS-NFS ............................ SKIPPED

[INFO] Apache Hadoop HDFS Project ........................ SKIPPED

[INFO] hadoop-yarn ....................................... SKIPPED

[INFO] hadoop-yarn-api ................................... SKIPPED

[INFO] hadoop-yarn-common ................................ SKIPPED

[INFO] hadoop-yarn-server ................................ SKIPPED

[INFO] hadoop-yarn-server-common ......................... SKIPPED

[INFO] hadoop-yarn-server-nodemanager .................... SKIPPED

[INFO] hadoop-yarn-server-web-proxy ...................... SKIPPED

[INFO] hadoop-yarn-server-resourcemanager ................ SKIPPED

[INFO] hadoop-yarn-server-tests .......................... SKIPPED

[INFO] hadoop-yarn-client ................................ SKIPPED

[INFO] hadoop-yarn-applications .......................... SKIPPED

[INFO] hadoop-yarn-applications-distributedshell ......... SKIPPED

[INFO] hadoop-mapreduce-client ........................... SKIPPED

[INFO] hadoop-mapreduce-client-core ...................... SKIPPED

[INFO] hadoop-yarn-applications-unmanaged-am-launcher .... SKIPPED

[INFO] hadoop-yarn-site .................................. SKIPPED

[INFO] hadoop-yarn-project ............................... SKIPPED

[INFO] hadoop-mapreduce-client-common .................... SKIPPED

[INFO] hadoop-mapreduce-client-shuffle ................... SKIPPED

[INFO] hadoop-mapreduce-client-app ....................... SKIPPED

[INFO] hadoop-mapreduce-client-hs ........................ SKIPPED

[INFO] hadoop-mapreduce-client-jobclient ................. SKIPPED

[INFO] hadoop-mapreduce-client-hs-plugins ................ SKIPPED

[INFO] Apache Hadoop MapReduce Examples .................. SKIPPED

[INFO] hadoop-mapreduce .................................. SKIPPED

[INFO] Apache Hadoop MapReduce Streaming ................. SKIPPED

[INFO] Apache Hadoop Distributed Copy .................... SKIPPED

[INFO] Apache Hadoop Archives ............................ SKIPPED

[INFO] Apache Hadoop Rumen ............................... SKIPPED

[INFO] Apache Hadoop Gridmix ............................. SKIPPED

[INFO] Apache Hadoop Data Join ........................... SKIPPED

[INFO] Apache Hadoop Extras .............................. SKIPPED

[INFO] Apache Hadoop Pipes ............................... SKIPPED

[INFO] Apache Hadoop Tools Dist .......................... SKIPPED

[INFO] Apache Hadoop Tools ............................... SKIPPED

[INFO] Apache Hadoop Distribution ........................ SKIPPED

[INFO] Apache Hadoop Client .............................. SKIPPED

[INFO] Apache Hadoop Mini-Cluster ........................ SKIPPED

[INFO] ------------------------------------------------------------------------

[INFO] BUILD FAILURE

[INFO] ------------------------------------------------------------------------

[INFO] Total time: 1.578s

[INFO] Finished at: Fri Aug 23 15:28:05 CST 2013

[INFO] Final Memory: 18M/52M

[INFO] ------------------------------------------------------------------------

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-enforcer-plugin:1.

3.1:enforce (clean) on project hadoop-main: Execution clean of goal org.apache.m

aven.plugins:maven-enforcer-plugin:1.3.1:enforce failed: Plugin org.apache.maven

.plugins:maven-enforcer-plugin:1.3.1 or one of its dependencies could not be res

olved: Could not find artifact commons-lang:commons-lang:jar:2.3 in nexus (http:

//172.21.77.119:8081/nexus/content/groups/public/) -> [Help 1]

[ERROR]

[ERROR] To see the full stack trace of the errors, re-run Maven with the -e swit

ch.

[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 rea

d the following articles:

[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginResoluti

onException

E:\hadoop-common-trunk>

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-enforcer-plugin:1.

3.1:enforce (clean) on project hadoop-main: Execution clean of goal org.apache.m

aven.plugins:maven-enforcer-plugin:1.3.1:enforce failed: Plugin org.apache.maven

.plugins:maven-enforcer-plugin:1.3.1 or one of its dependencies could not be res

olved:
Could not find artifact commons-lang:commons-lang:jar:2.3 in nexus (http:
//172.21.77.119:8081/nexus/content/groups/public/) -> [Help 1]

具体错误用红色标记出来了。

解决办法

1 去自己的.m2 文件夹下把 xxx.lastUpdated文件全部删掉  （无果）
2 在用maven时加 -U参数  （无果）
3 去nexus里去先"Update Index"再"Expire Cache"  （无果）

同时执行方案（2+3 ）成功。

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