org.apache.maven.plugin.MojoExecutionException: protoc failure

build   hadoop 23 真的是千辛万苦，错误贴出来

[ERROR] Failed to execute goal org.apache.hadoop:hadoop-maven-plugins:3.0.0-SNAPSHOT:protoc (compile-protoc) on project hadoop-c
 [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.hadoop:hadoop-maven-plugins:3.0.0-SNAP
plugin.MojoExecutionException: protoc failure
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:217)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:320)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
        at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
        at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
        at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
        at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)
Caused by: org.apache.maven.plugin.MojoExecutionException: org.apache.maven.plugin.MojoExecutionException: protoc failure
        at org.apache.hadoop.maven.plugin.protoc.ProtocMojo.execute(ProtocMojo.java:81)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
        ... 19 more
**Caused by: org.apache.maven.plugin.MojoExecutionException: protoc failure**
        at org.apache.hadoop.maven.plugin.protoc.ProtocMojo.execute(ProtocMojo.java:78)
        ... 21 more
[ERROR]
[ERROR]

wget http://protobuf.googlecode.com/files/protobuf-2.5.1.tar.gz
tar xzf protobuf-2.4.1.tar.gz
cd protobuf-2.4.1
./configure
make
sudo make install
sudo ldconfig

sudo ldconfig

亮点是我没有执行，sudo  ldconfig 这个命令，错误一致在，删除了respository 里面的google目录还是不行。

百度了一下，ldconfig的命令，

ldconfig命令的作用是：
ldconfig creates the necessary links and cache to the most recent shared libraries found in the directories specified on the command line, in the file /etc/ld.so.conf, and in the trusted directories (/lib and /usr/lib). The cache is used by the run-time linker, ld.so or ld-linux.so. ldconfig checks the header and filenames of the libraries it encounters when determining which versions should have their links updated.

ldconfig几个需要注意的地方！

1. 往/lib和/usr/lib里面加东西，是不用修改/etc/ld.so.conf的，但是完了之后要调一下ldconfig，不然这个library会找不到

2. 想往上面两个目录以外加东西的时候，一定要修改/etc/ld.so.conf，然后再调用ldconfig，不然也会找不到

比 如安装了一个mysql到/usr/local/mysql，mysql有一大堆library在/usr/local/mysql/lib下面，这时就 需要在/etc/ld.so.conf下面加一行/usr/local/mysql/lib，保存过后ldconfig一下，新的library才能在程 序运行时被找到。

3. 如果想在这两个目录以外放lib，但是又不想在/etc/ld.so.conf中加东西（或者是没有权限加东西）。那也可以，就是export一个全局变 量LD_LIBRARY_PATH，然后运行程序的时候就会去这个目录中找library。一般来讲这只是一种临时的解决方案，在没有权限或临时需要的时 候使用。

4. ldconfig做的这些东西都与运行程序时有关，跟编译时一点关系都没有。编译的时候还是该加-L就得加，不要混淆了。

5. 总之，就是不管做了什么关于library的变动后，最好都ldconfig一下，不然会出现一些意想不到的结果。不会花太多的时间，但是会省很多的事