php8 環境をセットアップする方法を段階的に説明します (一般的な問題の解決策も含めて)。

> cd /usr/local/src/
> tar xzf php-8.0.0.tar.gz
> cd php-8.0.0

./configure --prefix=/usr/local/php8 --with-config-file-path=/usr/local/php8/etc --with-fpm-user=www --with-fpm-group=www --with-curl --with-openssl --with-mysqli --with-pdo-mysql --with-iconv --with-mhash --with-zlib  --enable-mbstring  --enable-gd   --enable-gd-jis-conv --enable-sockets --enable-fpm --enable- --enable-xml  --enable-pdo  --enable-cli --enable-pcntl --enable-soap --enable-opcache --enable-fileinfo --disable-rpath --enable-mysqlnd --with-zip --enable-simplexml --with-libxml --with-sqlite3 --with-pdo-sqlite --enable-phar --enable-tokenizer --enable-cgi

configure: error: Package requirements (libxml-2.0 >= 2.9.0) were not met:
Package 'libxml-2.0', required by 'virtual:world', not found
Consider adjusting the PKG_CONFIG_PATH environment variable if you
installed software in a non-standard prefix.
Alternatively, you may set the environment variables LIBXML_CFLAGS
and LIBXML_LIBS to avoid the need to call pkg-config.
See the pkg-config man page for more details.

> yum install libxml2-devel

configure: error: Package requirements (sqlite3 > 3.7.4) were not met:

> yum install sqlite-devel

configure: error: Package requirements (libcurl >= 7.29.0) were not met:

> yum install libcurl-devel

configure: error: Package requirements (libpng) were not met:

> yum install libpng libpng-devel

configure: error: Package requirements (oniguruma) were not met:

> cd /usr/local/src/
> wget http://ftp.altlinux.org/pub/distributions/ALTLinux/Sisyphus/x86_64/RPMS.classic/liboniguruma5-6.9.6-alt1.x86_64.rpm -O liboniguruma5-6.9.6-alt1.x86_64.rpm
> rpm -ivh liboniguruma5-6.9.6-alt1.x86_64.rpm
> wget http://ftp.altlinux.org/pub/distributions/ALTLinux/Sisyphus/x86_64/RPMS.classic/liboniguruma-devel-6.9.6-alt1.x86_64.rpm -O liboniguruma-devel-6.9.6-alt1.x86_64.rpm 
> rpm liboniguruma-devel-6.9.6-alt1.x86_64.rpmcli

configure: error: Package requirements (libzip >= 0.11 libzip != 1.3.1 libzip != 1.7.0) were not met:

> yum install libzip libzip-devel

+--------------------------------------------------------------------+
| License:                                                           |
| This software is subject to the PHP License, available in this     |
| distribution in the file LICENSE. By continuing this installation  |
| process, you are bound by the terms of this license agreement.     |
| If you do not agree with the terms of this license, you must abort |
| the installation process at this point.                            |
+--------------------------------------------------------------------+
Thank you for using PHP.

make install

[root@54skyer php-8.0.0]# make install
Installing shared extensions:     /usr/local/php8/lib/php/extensions/no-debug-non-zts-20200930/
Installing PHP CLI binary:        /usr/local/php8/bin/
Installing PHP CLI man page:      /usr/local/php8/php/man/man1/
Installing PHP FPM binary:        /usr/local/php8/sbin/
Installing PHP FPM defconfig:     /usr/local/php8/etc/
Installing PHP FPM man page:      /usr/local/php8/php/man/man8/
Installing PHP FPM status page:   /usr/local/php8/php/php/fpm/
Installing phpdbg binary:         /usr/local/php8/bin/
Installing phpdbg man page:       /usr/local/php8/php/man/man1/
Installing PHP CGI binary:        /usr/local/php8/bin/
Installing PHP CGI man page:      /usr/local/php8/php/man/man1/
Installing build environment:     /usr/local/php8/lib/php/build/
Installing header files:          /usr/local/php8/include/php/
Installing helper programs:       /usr/local/php8/bin/
  program: phpize
  program: php-config
Installing man pages:             /usr/local/php8/php/man/man1/
  page: phpize.1
  page: php-config.1
/usr/local/src/php-8.0.0/build/shtool install -c ext/phar/phar.phar /usr/local/php8/bin/phar.phar
ln -s -f phar.phar /usr/local/php8/bin/phar
Installing PDO headers:           /usr/local/php8/include/php/ext/pdo/

> vim /etc/profile # 在文件末尾加入
# PATH=$PATH:/usr/local/php8/bin/
# export PATH
# :wq 保存并退出
> source /etc/profile # 立刻生效配置
> php -v # 获得如下信息

php -v
PHP 8.0.0 (cli) (built: Dec 15 2020 02:46:59) ( NTS )
Copyright (c) The PHP Group
Zend Engine v4.0.0-dev, Copyright (c) Zend Technologies

// 复制php.ini到编译配置参数指定的目录。php.ini在解压的源码目录里
> cp /usr/local/src/php-8.0.0/php.ini-production /usr/local/php8/etc/php.ini
// 复制一份php-fpm的配置模版文件到同级目录 方便备份和修改
> cp /usr/local/php8/etc/php-fpm.conf.default /usr/local/php8/etc/php-fpm.conf
// 复制一份php-fpm的扩展配置模板文件到同级目录 方便备份和修改
> cp /usr/local/php8/etc/php-fpm.d/www.conf.default /usr/local/php8/etc/php-fpm.d/www.conf
// 复制开启自起脚本到系统启动自动加载脚本目录。fpm/init.d.php-fpm在解压的源码目录里
> cp /usr/local/src/php-8.0.0/sapi/fpm/init.d.php-fpm /etc/init.d/php-fpm

> chmod +x /etc/init.d/php-fpm # 添加可执行权限

> service php-fpm start # 检验服务启动
> service php-fpm stop # 检验服务关闭
// 均正常提示
> chkconfig php-fpm on # 设置开机自动执行php-fpm开机自启动脚本
> reboot # 重启，ssh重连
# 重启后
[root@54skyer ~]# netstat -ntlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      1097/nginx: master  
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      1061/sshd           
tcp        0      0 0.0.0.0:16379           0.0.0.0:*               LISTEN      1090/redis-server 0 
tcp        0      0 127.0.0.1:9000          0.0.0.0:*               LISTEN      1083/php-fpm: maste

; include=fpm.d/*.conf