kill: --list output format differs from GNU #6197
Description
Environment: Ubuntu 20.04, uutils main branch (git commit 415de28), GNU coreutils version 9.5.3-8f39 (from git commit coreutils/coreutils@8f3989d).
The uutils version of kill --list prints all the signal names in one line, whereas recent GNU versions prints each signal name on its own line. (There are also more signals listed on my system, but this issue is only about the formatting.) This difference is causing the GNU test file tests/misc/kill.sh to ERROR.
uutils kill:
$ ./target/debug/kill -l
EXIT HUP INT QUIT ILL TRAP ABRT BUS FPE KILL USR1 SEGV USR2 PIPE ALRM TERM STKFLT CHLD CONT STOP TSTP TTIN TTOU URG XCPU XFSZ VTALRM PROF WINCH POLL PWR SYS
GNU kill:
$ ./kill -l
HUP
INT
QUIT
ILL
TRAP
ABRT
BUS
FPE
KILL
USR1
SEGV
USR2
PIPE
ALRM
TERM
STKFLT
CHLD
CONT
STOP
TSTP
TTIN
TTOU
URG
XCPU
XFSZ
VTALRM
PROF
WINCH
POLL
PWR
SYS
RTMIN
RTMIN+1
RTMIN+2
RTMIN+3
RTMIN+4
RTMIN+5
RTMIN+6
RTMIN+7
RTMIN+8
RTMIN+9
RTMIN+10
RTMIN+11
RTMIN+12
RTMIN+13
RTMIN+14
RTMIN+15
RTMAX-14
RTMAX-13
RTMAX-12
RTMAX-11
RTMAX-10
RTMAX-9
RTMAX-8
RTMAX-7
RTMAX-6
RTMAX-5
RTMAX-4
RTMAX-3
RTMAX-2
RTMAX-1
RTMAX