Description:
after update to at-3.2.4 and linux-5.16.4 the at command no longer executes at the specified time. In fact it waits for another at command before executing.

Additional info:
* package version(s) at-3.2.4 linux-5.16.4
* config and/or log files etc.
* link to upstream bug report, if any

Steps to reproduce:
I run this shell command
##############################################################################
#!/bin/sh
OUT=/tmp/atd-test-$$.out
trap "rm -f $OUT" EXIT
cat /dev/null > "$OUT"
chmod 666 "$OUT"
echo "date >> $OUT" | at now + 1 min
echo -e "\e[1;31m\xE2\x9D\x8C waiting\e[0m"
tail -F "$OUT" | \
while read line; do
echo -e "\e[1;32m\e[1A\e[K\xE2\x9C\x94 $line read OK\e[0m" && exit 0
done
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watching the clock shows that the command does not execute until another at command is executed. Example
robin@minikat:~
$ tatd
warning: commands will be executed using /bin/sh
job 4174 at Sat Feb 12 10:53:00 2022
❌ waiting
^C
robin@minikat:~
$ tatd
warning: commands will be executed using /bin/sh
job 4175 at Sat Feb 12 10:55:00 2022
❌ waiting
^C
robin@minikat:~
$ atrm 4175
robin@minikat:~

The journalctl -f output shows that the command executes when I run the second at command at 10:54; it should have executed at 10:53.
##############################################################################
Feb 12 10:54:15 minikat audit[2286]: USER_ACCT pid=2286 uid=2 auid=4294967295 ses=4294967295 msg='op=PAM:accounting grantors=pam_access,pam_unix,pam_time acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 10:54:15 minikat kernel: audit: type=1101 audit(1644663255.785:80): pid=2286 uid=2 auid=4294967295 ses=4294967295 msg='op=PAM:accounting grantors=pam_access,pam_unix,pam_time acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 10:54:15 minikat kernel: audit: type=1006 audit(1644663255.785:81): pid=2286 uid=2 old-auid=4294967295 auid=1000 tty=(none) old-ses=4294967295 ses=4 res=1
Feb 12 10:54:15 minikat kernel: audit: type=1300 audit(1644663255.785:81): arch=c000003e syscall=1 success=yes exit=4 a0=7 a1=7ffec05d5880 a2=4 a3=3e8 items=0 ppid=395 pid=2286 auid=1000 uid=2 gid=2 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4 comm="atd" exe="/usr/bin/atd" key=(null)
Feb 12 10:54:15 minikat kernel: audit: type=1327 audit(1644663255.785:81): proctitle=2F7573722F62696E2F617464002D66
Feb 12 10:54:15 minikat kernel: audit: type=1105 audit(1644663255.785:82): pid=2286 uid=2 auid=1000 ses=4 msg='op=PAM:session_open grantors=pam_loginuid,pam_limits,pam_unix acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 10:54:15 minikat kernel: audit: type=1103 audit(1644663255.785:83): pid=2286 uid=2 auid=1000 ses=4 msg='op=PAM:setcred grantors=pam_unix,pam_env acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 10:54:15 minikat audit[2286]: SYSCALL arch=c000003e syscall=1 success=yes exit=4 a0=7 a1=7ffec05d5880 a2=4 a3=3e8 items=0 ppid=395 pid=2286 auid=1000 uid=2 gid=2 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4 comm="atd" exe="/usr/bin/atd" key=(null)
Feb 12 10:54:15 minikat audit: PROCTITLE proctitle=2F7573722F62696E2F617464002D66
Feb 12 10:54:15 minikat audit[2286]: USER_START pid=2286 uid=2 auid=1000 ses=4 msg='op=PAM:session_open grantors=pam_loginuid,pam_limits,pam_unix acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 10:54:15 minikat audit[2286]: CRED_ACQ pid=2286 uid=2 auid=1000 ses=4 msg='op=PAM:setcred grantors=pam_unix,pam_env acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 10:54:15 minikat atd[2286]: pam_unix(atd:session): session opened for user robin(uid=1000) by (uid=2)
Feb 12 10:54:15 minikat atd[2286]: pam_env(atd:setcred): deprecated reading of user environment enabled
Feb 12 10:54:15 minikat atd[2286]: pam_env(atd:setcred): deprecated reading of user environment enabled
Feb 12 10:54:15 minikat audit[2286]: CRED_DISP pid=2286 uid=2 auid=1000 ses=4 msg='op=PAM:setcred grantors=pam_unix,pam_env acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 10:54:15 minikat audit[2286]: USER_END pid=2286 uid=2 auid=1000 ses=4 msg='op=PAM:session_close grantors=pam_loginuid,pam_limits,pam_unix acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 10:54:15 minikat atd[2286]: pam_unix(atd:session): session closed for user robin
Feb 12 10:54:15 minikat kernel: audit: type=1104 audit(1644663255.792:84): pid=2286 uid=2 auid=1000 ses=4 msg='op=PAM:setcred grantors=pam_unix,pam_env acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 10:54:15 minikat kernel: audit: type=1106 audit(1644663255.792:85): pid=2286 uid=2 auid=1000 ses=4 msg='op=PAM:session_close grantors=pam_loginuid,pam_limits,pam_unix acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
##############################################################################

A good run looks like this

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This is the good run with linux-5.16.3.arch1-1-x86_64 and at-3.2.2-1-x86_64
Linux minikat 5.16.3-arch1-1 #1 SMP PREEMPT Thu, 27 Jan 2022 14:18:25 +0000 x86_64 GNU/Linux

$ tatd
warning: commands will be executed using /bin/sh
job 4180 at Sat Feb 12 11:28:00 2022
✔ Sat 12 Feb 11:28:00 GMT 2022 read OK
robin@minikat:~
#no need for another run as the first has worked as expected
##############################################################################
This is the good run with linux-5.16.3.arch1-1-x86_64 and at-3.2.2-1-x86_64
Linux minikat 5.16.3-arch1-1 #1 SMP PREEMPT Thu, 27 Jan 2022 14:18:25 +0000 x86_64 GNU/Linux

Feb 12 11:28:00 minikat audit[1649]: USER_ACCT pid=1649 uid=2 auid=4294967295 ses=4294967295 msg='op=PAM:accounting grantors=pam_access,pam_unix,pam_time acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 11:28:00 minikat audit[1649]: SYSCALL arch=c000003e syscall=1 success=yes exit=4 a0=7 a1=7fff512527b0 a2=4 a3=3e8 items=0 ppid=364 pid=1649 auid=1000 uid=2 gid=2 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4 comm="atd" exe="/usr/bin/atd" key=(null)
Feb 12 11:28:00 minikat audit: PROCTITLE proctitle=2F7573722F62696E2F617464002D66
Feb 12 11:28:00 minikat audit[1649]: USER_START pid=1649 uid=2 auid=1000 ses=4 msg='op=PAM:session_open grantors=pam_loginuid,pam_limits,pam_unix acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 11:28:00 minikat audit[1649]: CRED_ACQ pid=1649 uid=2 auid=1000 ses=4 msg='op=PAM:setcred grantors=pam_unix,pam_env acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 11:28:00 minikat atd[1649]: pam_unix(atd:session): session opened for user robin(uid=1000) by (uid=2)
Feb 12 11:28:00 minikat atd[1649]: pam_env(atd:setcred): deprecated reading of user environment enabled
Feb 12 11:28:00 minikat kernel: audit: type=1101 audit(1644665280.896:83): pid=1649 uid=2 auid=4294967295 ses=4294967295 msg='op=PAM:accounting grantors=pam_access,pam_unix,pam_time acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 11:28:00 minikat kernel: audit: type=1006 audit(1644665280.896:84): pid=1649 uid=2 old-auid=4294967295 auid=1000 tty=(none) old-ses=4294967295 ses=4 res=1
Feb 12 11:28:00 minikat kernel: audit: type=1300 audit(1644665280.896:84): arch=c000003e syscall=1 success=yes exit=4 a0=7 a1=7fff512527b0 a2=4 a3=3e8 items=0 ppid=364 pid=1649 auid=1000 uid=2 gid=2 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4 comm="atd" exe="/usr/bin/atd" key=(null)
Feb 12 11:28:00 minikat kernel: audit: type=1327 audit(1644665280.896:84): proctitle=2F7573722F62696E2F617464002D66
Feb 12 11:28:00 minikat kernel: audit: type=1105 audit(1644665280.896:85): pid=1649 uid=2 auid=1000 ses=4 msg='op=PAM:session_open grantors=pam_loginuid,pam_limits,pam_unix acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 11:28:00 minikat kernel: audit: type=1103 audit(1644665280.896:86): pid=1649 uid=2 auid=1000 ses=4 msg='op=PAM:setcred grantors=pam_unix,pam_env acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 11:28:00 minikat kernel: audit: type=1104 audit(1644665280.903:87): pid=1649 uid=2 auid=1000 ses=4 msg='op=PAM:setcred grantors=pam_unix,pam_env acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 11:28:00 minikat kernel: audit: type=1106 audit(1644665280.903:88): pid=1649 uid=2 auid=1000 ses=4 msg='op=PAM:session_close grantors=pam_loginuid,pam_limits,pam_unix acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 11:28:00 minikat audit[1649]: CRED_DISP pid=1649 uid=2 auid=1000 ses=4 msg='op=PAM:setcred grantors=pam_unix,pam_env acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 11:28:00 minikat audit[1649]: USER_END pid=1649 uid=2 auid=1000 ses=4 msg='op=PAM:session_close grantors=pam_loginuid,pam_limits,pam_unix acct="robin" exe="/usr/bin/atd" hostname=? addr=? terminal=? res=success'
Feb 12 11:28:00 minikat atd[1649]: pam_env(atd:setcred): deprecated reading of user environment enabled
Feb 12 11:28:00 minikat atd[1649]: pam_unix(atd:session): session closed for user robin