PHP warnings when using variables

if i use a variable in a php block it works fine but i’m getting php notices if i enable php debugging…

PHP Notice: Use of undefined constant ttx - assumed 'ttx' in /home/bytesorg/public_html/wp-content/plugins/global-content-blocks/global-content-blocks.php(322) : eval()'d code on line 1

sample php block…

$str = file_get_contents('/home/user/public_files/apps/' . %%appdir%% . '/changelog.txt');
if($str) {
  $str = nl2br($str);
} else {
  $str = 'No change log is available';
}
echo $str;

sample short-code…
[contentblock id=16 appdir="ttx"]

since this is only a php ‘notice’, i suspect it’s nothing to worry about, but i just want to be sure

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