df: fails to print filesystem when argument is .

[jfinkels]

df is able to find my root filesystem if I run it without any other arguments:

$ ./target/debug/df | grep ubuntu
/dev/mapper/vgubuntu-root 248618848256  94480936960 154137911296   38% /               

but if I run df ., it does not print my root filesystem

Filesystem          1k-blocks         Used    Available  Use% Mounted on 

Contrast this with GNU df:

$ df .
Filesystem                1K-blocks     Used Available Use% Mounted on
/dev/mapper/vgubuntu-root 242791844 92266552 138122400  41% /

[crazystylus]

I think there is more to this issue. I have verified, if I have a partition mounted at /root and I have a folder /root/docs then df /root/docs should print the details /root. And similarly if docs folder doesn't exist, it should pop an error No such file or directory.

But in both cases output here is empty