Description of problem:
I was trying to reproduce https://bugzilla.redhat.com/show_bug.cgi?id=1729197 on Fedora 32.

$ cat /etc/sysconfig/nftables.conf
table inet filter {
        include "/etc/nftables/customer/*"
}
$ mkdir -p /etc/nftables/customer
$ touch /etc/nftables/customer/f{00,01,02,03,04,05,06,07,08,09,10,11,12,13,14}
$ cat /etc/nftables/customer/f01
set s1 {
    type ipv4_addr
    flags constant,interval
}

set s2 {
    type ipv4_addr
    flags constant,interval
    elements = {
    1.1.1.1
    }
}
$ systemctl reload nftables

Version-Release number of selected component:
1:nftables-0.9.3-2.fc32

Additional info:
reporter:       libreport-2.12.0
backtrace_rating: 4
cgroup:         0::/system.slice/nftables.service
cmdline:        /sbin/nft flush ruleset; include "/etc/sysconfig/nftables.conf";
crash_function: scanner_destroy
executable:     /usr/sbin/nft
journald_cursor: s=28b09b4b69d44de48d5feae824fe6ed1;i=623;b=f41923afbe644ef1832404701bc92893;m=15a5be1b;t=5a48baa8f6ed2;x=2f930f22aa8edccb
kernel:         5.6.7-300.fc32.x86_64
rootdir:        /
runlevel:       N 3
type:           CCpp
uid:            0

Truncated backtrace:
Thread no. 1 (2 frames)
 #1 scanner_destroy at scanner.l:944
 #2 nft_run_cmd_from_buffer at libnftables.c:468