使用 CentOS Linux 版本 7.2.1511 (核心) 并运行 PHP 5.5.38 (cli) (构建时间：2016 年 7 月 21 日 12:25:20)。尝试安装 php-xml 但收到以下问题：
sudo yum install php-xml
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
* epel: mirror.symnds.com
* webtatic: us-east.repo.webtatic.com
Resolving Dependencies
--> Running transaction check
---> Package php-xml.x86_64 0:5.4.16-36.3.el7_2 will be installed
--> Processing Dependency: php-common(x86-64) = 5.4.16-36.3.el7_2 for package: php-xml-5.4.16-36.3.el7_2.x86_64
--> Running transaction check
---> Package php-common.x86_64 0:5.4.16-36.3.el7_2 will be installed
--> Processing Conflict: php55w-common-5.5.38-1.w7.x86_64 conflicts php-common < 5.5
--> Finished Dependency Resolution
Error: php55w-common conflicts with php-common-5.4.16-36.3.el7_2.x86_64
You could try using --skip-broken to work around the problem
You could try running: rpm -Va --nofiles --nodigest
如果我执行“yum list installed php”，它会显示以下内容：
yum list installed php*
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
* epel: mirror.symnds.com
* webtatic: us-east.repo.webtatic.com
Installed Packages
php55w.x86_64 5.5.38-1.w7 @webtatic
php55w-cli.x86_64 5.5.38-1.w7 @webtatic
php55w-common.x86_64 5.5.38-1.w7 @webtatic
php55w-mysql.x86_64 5.5.38-1.w7 @webtatic
php55w-pdo.x86_64 5.5.38-1.w7 @webtatic
我没有看到任何已安装的 PHP 5.4 包。有什么建议吗？