1.github下载protobuf： https://github.com/google/protobuf
2.解压：unzip protobuf-master.zip
3.转换到protobuf-master文件夹：cd protobuf-master
4.执行：./autogen.sh
出错：因为google.com被墙了，虚拟机里无法下载gtest，需要手动下载googletest-release-1.5.0.zip,解压缩后，改名为gtest放在protobuf-master目录下
googletest下载地址:https://github.com/google/googletest/releases
解决：unzip googletest-release-1.10.0.zip
把googletest-release-1.10.0放入protobuf-master/third_party文件夹中，删除原来的googletest，再将googletest-release-1.10.0命名为googletest
5. 再执行：./autogen.sh
出错：./autogen.sh: line : autoreconf: command not found（缺少autoconf这个工具安装）
解决：sudo apt-get install autoconf
出错：出现apt-get: Package has no installation candidate问题
解决：sudo apt-get update
出错：错误为”Failed to fetch 404 Not Found”
解决：cd /etc/apt
sudo vim sources.list
重新替换为下面的路径:
deb http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse
6.再执行：sudo apt-get update
出错：The repository 'http://ppa.launchpad.net/shutter/ppa/ubuntu disco Release' does not have a Release file.
解决：删除对应文件：sudo apt-add-repository -r ppa:shutter/ppa
7.再执行：sudo apt-get upgrade
8.再执行：sudo apt-get install autoconf
9.再执行： ./autogen.sh
出错：+ mkdir -p third_party/googletest/m4
+ autoreconf -f -i -Wall,no-obsolete
configure.ac:109: error: possibly undefined macro: AC_PROG_LIBTOOL
If this token and others are legitimate, please use m4_pattern_allow.
See the Autoconf documentation.
autoreconf: /usr/bin/autoconf failed with exit status: 1
解决：sudo apt-get install libtool
10.再执行：./autogen.sh
11.执行：./configure
12.执行：make
13.执行：make check
出错：
Making check in .
make[1]: Entering directory '/home/chanyeol/Downloads/protobuf-master'
make check-local
make[2]: Entering directory '/home/chanyeol/Downloads/protobuf-master'
Making lib/libgmock.a lib/libgmock_main.a in gmock
make[3]: Entering directory '/home/chanyeol/Downloads/protobuf-master/third_party/googletest/googletest'
make[3]: *** No rule to make target 'lib/libgtest.la'. Stop.
make[3]: Leaving directory '/home/chanyeol/Downloads/protobuf-master/third_party/googletest/googletest'
make[2]: *** [Makefile:2264: check-local] Error 2
make[2]: Leaving directory '/home/chanyeol/Downloads/protobuf-master'
make[1]: *** [Makefile:2127: check-am] Error 2
make[1]: Leaving directory '/home/chanyeol/Downloads/protobuf-master'
make: *** [Makefile:1839: check-recursive] Error 1
暂时找不到解决方法，但是没有影响。
14.执行：sudo make install
15.执行：protoc --version
出错：protoc: error while loading shared libraries: libprotoc.so.23: cannot open shared object file: No such file or directory
解决方法可参考博客：https://blog.csdn.net/xocoder/article/details/9155901
解决： cd /etc/ld.so.conf.d
sudo touch libprotobuf.conf
sudo vim libprotobuf.conf ，插入内容：/usr/local/lib
sudo ldconfig
16.再执行：protoc --version
