If seems that there are many cases where we define self-conflicts, but GNU accepts repeated arguments. This is especially unnecessary for boolean flags. Let's fix that! This issue tracks progress for all utils.

• chgrp: at least -v is broken
• chmod: not considered yet
• chown: not considered yet
• chroot: not considered yet
• comm: at least -1 is broken
• cp: at least -a is handled correctly
• csplit: at least -k is broken
• date: at least --resolution is broken: date: implement --resolution #6143 , rest is fixed by date: fix interaction of flags, fix issues around --set #6142
• du: at least -s is broken
• echo: at least -n is broken
• fmt: at least -c is broken, fixed by fmt: accept repeated arguments #6355
• fold: at least -b is broken
• id: at least -u is broken
• install: at least -b is broken
• join: at least -z is broken
• kill: at least -l is broken
• ln: not considered yet
• logname: not considered yet
• ls: not considered yet
• mkdir: not considered yet
• mkfifo: not considered yet
• mknod: not considered yet
• mktemp: not considered yet
• more: not considered yet
• mv: not considered yet
• nice: not considered yet
• nl: not considered yet
• nohup: not considered yet
• nproc: not considered yet
• numfmt: not considered yet
• od: not considered yet
• paste: not considered yet
• pathchk: not considered yet
• pinky: not considered yet
• pr: not considered yet
• printenv: not considered yet
• printf: not considered yet
• ptx: not considered yet
• pwd: not considered yet
• readlink: not considered yet
• realpath: not considered yet
• rm: not considered yet
• rmdir: not considered yet
• runcon: not considered yet
• seq: not considered yet
• shred: not considered yet
• sleep: not considered yet
• sort: at least --sort=month --sort=numeric is broken
• split: not considered yet
• stat: not considered yet
• stdbuf: not considered yet
• stty: not considered yet
• sum: not considered yet
• sync: not considered yet
• tac: not considered yet
• tail: not considered yet
• tee: not considered yet
• test: not considered yet
• timeout: not considered yet
• touch: not considered yet
• truncate: not considered yet
• tsort: not considered yet
• tty: not considered yet
• uname: not considered yet
• unexpand: not considered yet
• uniq: not considered yet
• unlink: not considered yet
• uptime: not considered yet
• users: not considered yet
• vdir: not considered yet
• wc: not considered yet
• who: not considered yet