unable to open printf, unable to read file [duplicate]

i am trying to debug a ".c" file in vs code in my ubuntu machine, but i am having this issue.

 Unable to open 'printf.c': Unable to read file (Error: File not found (/build/glibc-OTsEL5/glibc-2.27/stdio-common/printf.c)).

after i say "Create File" it gives this error

Unable to write file (NoPermissions (FileSystemError): Error: EACCES: permission denied, mkdir '/build')

i am trying to debug a simple "hello world" code. also in any function like, malloc etc. it gives the same error outline.

what might be the problem and the solution?

Launch.json

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "gcc build and debug active file",
            "type": "cppdbg",
            "request": "launch",
            "program": "${fileDirname}/${fileBasenameNoExtension}",
            "args": [],
            "stopAtEntry": false,
            "cwd": "${workspaceFolder}",
            "environment": [],
            "externalConsole": true,
            "MIMode": "gdb",
            "setupCommands": [
                {
                    "description": "Enable pretty-printing for gdb",
                    "text": "-enable-pretty-printing",
                    "ignoreFailures": true
                }
            ],
            "preLaunchTask": "gcc build active file",
            "miDebuggerPath": "/usr/bin/gdb"
        }
    ]
}

Tasks.json

{
    // See https://go.microsoft.com/fwlink/?LinkId=733558 
    // for the documentation about the tasks.json format
    "version": "2.0.0",
    "tasks": [
        {
            "type": "shell",
            "label": "gcc build active file",
            "command": "/usr/bin/gcc",
            "args": [
                "-g",
                "${file}",
                "-o",
                "${fileDirname}/${fileBasenameNoExtension}"
            ],
            "options": {
                "cwd": "/usr/bin"
            },
            "problemMatcher": [
                "$gcc"
            ],
            "group": "build"
        }
    ]
}