mkdir无法正常工作-终端突然崩溃

Some days ago I have installed Debian 10 buster on a fresh system. Everything seemed to work fine, until now. I've tried to use mkdir foo and the terminal window closed/crashed (XTerm, i3wm). Even more weird: if I use Nautilus/Files file-manager everything seems to work.

One significant change I've done some days ago (without any recognizable negative effects) is change the permissions (recursively) for the home-files and directory to -rwx------ and drwx------ respectively.

(如果能得到一些有用的诊断命令以缩小问题范围,将不胜感激。无法与笔记本电脑同步同步。)

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$ ls -l `which mkdir`
-rwxr-xr-x 1 root root 89088 Feb 28  2019 /usr/bin/mkdir

$ sha256sum `which mkdir`
49bcc51087a41459b4b2304d05ee50f9c8e217fc23548cd80f13d1d89a6269bf  /usr/bin/mkdir

(same for the $-variant)

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更新2 @斯蒂芬·夏泽拉斯

$ type mkdir
mkdir is a function
mkdir () 
{ 
    mkdir -p "$1" && cd "$1"
}

$ (mkdir foo)
Segmentation fault

Big Thank You! Solved! Some time ago I've created an alias – mc – for creating and entering a new directory. It worked fine. However yesterday I've tried 'midnight commander' and changed the alias since mc was now required for the new app.

Extract from my .bash_aliases file (now, with mc as a function again, which works)

alias md='mkdir'
mc()
{                                                       
      mkdir -p "$1" && cd "$1"                                         
}

Now I've removed midnight commander (was not really impressive) and re-named, re-sourced and rebooted; and now it works fine again!