@frendsick could you please have a look? Thanks

Where can I find the failing configure scripts?

I'm building a system following LFS project, and use uutils instead of coreutils. then the check package can't be configured before i dropped the --disable-static option. rerunning with bash -x and i found the fail case in this issue.
The latest released version of uutils is ok.

Where can I find the failing configure scripts?

I looked through the changes, and it seems we need a way to distinguish the '^' character: the beginning position or 'a character not in the following list'

Thank you for the help, I see the problem. I verified that the GNU expr does use the ^ character as the character class negation when it is the first character after [ inside a character class.

I will try to fix this.

Thank you for the help, I see the problem. I verified that the GNU expr does use the ^ character as the character class negation when it is the first character after [ inside a character class.

I will try to fix this.

Great, glad to hear that.

@zhw2101024 I created PR #7884 that should fix this. Please test the changes if you want.

@zhw2101024 I created PR #7884 that should fix this. Please test the changes if you want.

The configure script works well with PR #7884. Looks good to me.