Comment 24 for bug 1872118

error in the above description should have been
I've done the apt install on one of SERVERS the failover server (Its the one that mostly crashes)

Listing... Done
isc-dhcp-server/focal,now 4.4.1-2.1ubuntu6~ppa1 amd64 [installed]

still crashed

syslog shows
Aug 4 17:40:44 gw2-focal sh[74365]: ../../../../lib/isc/unix/socket.c:3361: INSIST(!sock->pending_send) failed, back trace
Aug 4 17:40:44 gw2-focal sh[74365]: #0 0x7f2302a7fa4a in ??
Aug 4 17:40:44 gw2-focal sh[74365]: #1 0x7f2302a7f980 in ??
Aug 4 17:40:44 gw2-focal sh[74365]: #2 0x7f2302abb7e1 in ??
Aug 4 17:40:44 gw2-focal sh[74365]: #3 0x7f2302862609 in ??
Aug 4 17:40:44 gw2-focal sh[74365]: #4 0x7f230299e103 in ??
Aug 4 17:40:44 gw2-focal systemd[1]: isc-dhcp-server.service: Main process exited, code=killed, status=6/ABRT
Aug 4 17:40:44 gw2-focal systemd[1]: isc-dhcp-server.service: Failed with result 'signal'.

text part of crash shows

ProblemType: Crash
Architecture: amd64
Date: Tue Aug 4 17:44:17 2020
DistroRelease: Ubuntu 20.04
ExecutablePath: /usr/sbin/dhcpd
ExecutableTimestamp: 1596511208
ProcCmdline: dhcpd -user dhcpd -group dhcpd -f -4 -pf /run/dhcp-server/dhcpd.pid -cf /etc/dhcp/dhcpd.conf
ProcEnviron: Error: [Errno 13] Permission denied: 'environ'
ProcMaps: Error: [Errno 13] Permission denied: 'maps'
ProcStatus:
 Name: dhcpd
 Umask: 0022
 State: D (disk sleep)
 Tgid: 74528
 Ngid: 0
 Pid: 74528
 PPid: 1
 TracerPid: 0
 Uid: 113 113 113 113
 Gid: 118 118 118 118
 FDSize: 128
 Groups:
 NStgid: 74528
 NSpid: 74528
 NSpgid: 74528
 NSsid: 74528
 VmPeak: 235996 kB
 VmSize: 170540 kB
 VmLck: 0 kB
 VmPin: 0 kB
 VmHWM: 12088 kB
 VmRSS: 11904 kB
 RssAnon: 5784 kB
 RssFile: 6120 kB
 RssShmem: 0 kB
 VmData: 30568 kB
 VmStk: 132 kB
 VmExe: 592 kB
 VmLib: 5424 kB
 VmPTE: 88 kB
 VmSwap: 0 kB
 HugetlbPages: 0 kB
 CoreDumping: 1
 THP_enabled: 1
 Threads: 4
 SigQ: 0/31897
 SigPnd: 0000000000000000
 ShdPnd: 0000000000000000
 SigBlk: 0000000000000000
 SigIgn: 0000000000001000
 SigCgt: 0000000180000000
 CapInh: 0000000000000000
 CapPrm: 0000000000000000
 CapEff: 0000000000000000
 CapBnd: 0000003fffffffff
 CapAmb: 0000000000000000
 NoNewPrivs: 0
 Seccomp: 0
 Speculation_Store_Bypass: thread vulnerable
 Cpus_allowed: f
 Cpus_allowed_list: 0-3
 Mems_allowed: 00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,0000
0000,00000000,00000000,00000001
 Mems_allowed_list: 0
 voluntary_ctxt_switches: 22
 nonvoluntary_ctxt_switches: 20
Signal: 6
Uname: Linux 5.4.0-42-generic x86_64
UserGroups: N/A
CoreDump: base64