I am creating the bcompiled file using:

<?php
$fhandle = fopen('test.php', 'w');
bcompiler_write_header($fhandle);
bcompiler_write_file($fhandle, 'test.phb');
bcompiler_write_footer($fhandle);
fclose($fhandle);
?>

If the source file is test.php, and bytecodes are to be written to test.phb, you need to use it as follows:

<?php
$fhandle = fopen('test.phb', 'w');   // here comes the bytecode file name
bcompiler_write_header($fhandle);
bcompiler_write_file($fhandle, 'test.php'); // here comes the source file name
bcompiler_write_footer($fhandle);
fclose($fhandle);
?>

In my application, I was trying to write to the same file as the source file.

You can close this bug.