Installation Error, 502 Bad Gateway, from page /install/index.php

I followed the installation document https://docs.vvveb.com/installation / setting up nginx & php, trying to access localhost:8080, then got below error:

It can be seen that the error occurred on the /install/index.php page.

My development environment is as follows.

php

nginx

#user  nobody;
worker_processes  1;

error_log  logs/error.log  notice;
#error_log  logs/error.log  info;

#pid        logs/nginx.pid;

events {
    worker_connections  1024;
}

http {

    fastcgi_cache_path /var/run/nginx-vvveb_cache levels=1:2 keys_zone=VCACHE:100m inactive=30m;
    fastcgi_cache_key "$scheme$request_method$host$request_uri";
    fastcgi_cache_use_stale error timeout invalid_header http_500;

    #sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    #keepalive_timeout  65;

    #gzip  on;

    server {
        listen       0.0.0.0:8080;
        server_name  localhost;

        #root html;
        root /usr/local/var/vvveb/public;
        index index.php index.html index.htm;

        #charset koi8-r;

        #access_log  logs/host.access.log  main;

        gzip on;
        gzip_vary on;
        gzip_min_length 10240;
        gzip_proxied any;
        gzip_comp_level 6;
        gzip_buffers 16 8k;
        gzip_http_version 1.1;
        gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

        #charset utf-8;

        add_header X-Frame-Options "SAMEORIGIN";
        add_header X-XSS-Protection "1; mode=block";
        add_header X-Content-Type-Options "nosniff";

        set $skip_cache 0;
        set $cache_uri $request_uri;

        if ($query_string != "") {
            set $skip_cache 1;
            set $cache_uri null;
        }

        # Don't cache uris containing the following segments
        if ($request_uri ~* "/admin/|/user/|/cart/|/feed/|index.php|sitemap(_index)?.xml") {
            set $skip_cache 1;
            set $cache_uri null;
        }  

        # Don't use the cache for logged in users or if products in cart
        if ($http_cookie ~* "nocache|user|cart") {
            set $skip_cache 1;
            set $cache_uri null;
        }

        # POST requests and urls with a query string should always go to PHP
        if ($request_method = POST) {
            set $skip_cache 1;
            set $cache_uri null;
        }

        #add domain to sitemaps for multisite
        location = /robots.txt {
            log_not_found off;
            access_log off;
            try_files $uri /index.php$is_args$args;
        }

        #static files   
        location ~* "\.(?!php)([\w]{3,5})$" {
            expires max;
            log_not_found off;
            sendfile           on;
            sendfile_max_chunk 1m;
            fastcgi_hide_header "Set-Cookie";
        }

        location / {
            #try_files $uri $uri/ =404;
            default_type  text/html;
            index index.php index.html index.htm;
            try_files /page-cache/$http_host$cache_uri /page-cache/$http_host$cache_uri/index.html $uri $uri/ /index.php$is_args$args;
            #try_files $uri $uri/ /index.php$is_args$args;

            #cache debug
            #add_header "uri" $cache_uri;
            #add_header "skip_cache" $skip_cache;
        }

        location ~ /media/.+?\.php$ {
            deny all;
        }

        location ~ \.php$ {
            include fastcgi.conf;
            fastcgi_pass 127.0.0.1:9000;
            fastcgi_index index.php;
            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;

            fastcgi_intercept_errors        on;

            #uncomment fastcgi_cache to enable fastcgi cache, this should not be necessary
            #unless you set the path to a memory mapped location for even faster cache

            #fastcgi_cache VCACHE;          
            fastcgi_cache_bypass $skip_cache;
            fastcgi_no_cache $skip_cache;
            fastcgi_cache_valid 30m;
            #add_header X-VCache $upstream_cache_status;  
        }

        location ~ /\.(?!well-known).* {
            deny all;
        }
}

I found some error info in Nginx log, but I didn't know what led to it.

I tried to put a simple php file as test, it works well.

<?php 
phpinfo(); 
?>

givanz / Vvveb

Installation Error, 502 Bad Gateway, from page /install/index.php #217