Running CentOS 7 as operation system for Rails is very stable, but such stability comes with stagnation, for example, the sqlite3 version is 3.7 instead of 3.8, so cause Rails 6 refused to run in CentOS 7 withouth install a third party sqlite3 version.

So a quickly fix is install atomic sqlite and setting the correct build options.

$HOME/.rbenv/bin/rbenv exec bundle config build.sqlite3 "--with-sqlite3-include=/opt/atomic/atomic-sqlite/root/usr/include --with-sqlite3-lib=/opt/atomic/atomic-sqlite/root/usr/lib64 --with-sqlite3-dir=/opt/atomic/atomic-sqlite/root/usr"

Maybe also need to do a patch but any way, I successfully upgrade to Rails 6.