warnings for Linux command “du -h –max-depth=1”.

359M ./boot
0 ./dev
du: cannot access ‘./proc/1302735/task/1302741/fdinfo/30’: No such file or directory
du: cannot access ‘./proc/1302735/task/1302744/fdinfo/30’: No such file or directory
du: cannot access ‘./proc/1302735/task/1302747/fd/30’: No such file or directory
du: cannot access ‘./proc/1302735/task/1302747/fd/31’: No such file or directory
du: cannot access ‘./proc/1302978/task/1302978/fd/3’: No such file or directory
du: cannot access ‘./proc/1302978/task/1302978/fdinfo/3’: No such file or directory
du: cannot access ‘./proc/1302978/fd/4’: No such file or directory
du: cannot access ‘./proc/1302978/fdinfo/4’: No such file or directory
0 ./proc
26M ./run
0 ./sys
3.6G ./etc
36G ./root

I wonder how to fix it.