I hope this is the right place for a bug report.

slowlog option of php-fpm uses prace to log a trace dump of the script; this is not allowed by the selinux policy.

Tested on php-fpm-7.3.8-1.el7.remi.x86_64, nginx-1.17.3-1.el7.ngx.x86_64, CentOS Linux release 7.6.1810 (Core)

I solved the issue with a custom selinux module:

require {
    type ht tpd_t;
    class process ptrace;
    class capability sys_ptrace;
}

#============= httpd_t ==============
allow ht tpd_t self:process ptrace;
allow ht tpd_t self:capability sys_ptrace;

(I had to add whitespaces in "ht tpd_t" because the forum says "Too more links in message. Allowed 1 links. Reduce number of links and post it again.")

Can you, please, add this to next packages?