Call stack:

Array
(
    [0] => Array
        (
            [function_name] => a
            [filename] => /var/www/localhost/htdocs/jeyk/test.php
            [linenum] => 23
        )

    [1] => Array
        (
            [function_name] => b
            [filename] => /var/www/localhost/htdocs/jeyk/test.php
            [linenum] => 5
        )

    [2] => Array
        (
            [function_name] => c
            [filename] => /var/www/localhost/htdocs/jeyk/test.php
            [linenum] => 10
        )

)

Generating a runtime error:

Warning: Invalid argument supplied for foreach() in /var/www/localhost/htdocs/jeyk/test.php on line 19

Traceback
Frame	Call to Function	Filename	Line Number
3	c	/var/www/localhost/htdocs/jeyk/test.php	10
2	b	/var/www/localhost/htdocs/jeyk/test.php	5
1	a	/var/www/localhost/htdocs/jeyk/test.php	23