Unable to invoke "dot" to create image file (code 127)

[sardjn]

I get this error:

Unable to invoke "dot" to create image file (code 127)

I have installed the graphviz, I have tried to reinstall it again, but I still get the same error.

Using Yii2, controller action:

public function actionGraph()
{
    $dir = Yii::getAlias('@app') . '/vendor';
    $graphComposer = new \Clue\GraphComposer\Graph\GraphComposer($dir);
    $graph = $graphComposer->createGraph();

    $graphviz = new \Graphp\GraphViz\GraphViz();
    $graphviz->setFormat('svg');
    $svg = $graphviz->createImageFile($graph);
    return $this->render('graph', ['svg' => $svg]);
}

and view:

<?php

/**
 * @var $this yii\web\View
 * @var $svg string
 */

var_dump($svg);
use yii\helpers\Html;

$this->title = 'Dependency Graph';
$this->params['breadcrumbs'][] = $this->title;

?>

<div class="site-dependency-graph">
    <h1><?= Html::encode($this->title) ?></h1><br />

    <div id="graph-placeholder">
        <!-- place here the svg file -->
        <?= $svg ?>
    </div>
</div>

[SimonFrings]

Hey @elementallos, thanks for bringing this up 👍

Like @clue described in graphp/graphviz#31, the Unable to invoke "dot" to create image file (code 127)... error message means you do not have GraphViz installed (the dot executable is part of the GraphViz package). On Debian/Ubuntu-based system you may simply install it like this:

$ sudo apt install graphviz

This has been answered in #4 as well and is also mentioned inside the documentation.
Ref: #43

I believe this should answer your question, so I will close this ticket for now. We can reopen this if you encounter the same issues again after trying out the solutions mentioned in here.

[sardjn]

But is not working anyway for me...
As I said already, in the first message, I have already tried to do:

$ sudo apt install graphviz

but is still not working. It's like the installation is not successful, even though I have no errors.

[SimonFrings]

As I said already, in the first message, I have already tried to do:

$ sudo apt install graphviz

You're right, so this would mean you can't even try dot -v to check the GraphViz version, right?

[sardjn]

Yes, I can do dot -v, it is only on the PHP code, when I try to generate the .svg
The installation with sudo apt install is successful: I don't get any error messages. But when I try to use the command, it looks like this (var_dump):

'dot' -T 'svg' '/tmp/graphvizDEdKjJ' -o '/tmp/graphvizDEdKjJ.svg'

Edit: I have also tried to paste the command in the terminal to see what could possibly happen. This is the result:

gabriel@HP:~ dot -T 'svg' '/tmp/graphvizDEdKjJ' -o '/tmp/graphvizDEdKjJ.svg'
Error: dot: can't open /tmp/graphvizDEdKjJ

[sardjn]

@SimonFrings any updates?

[SimonFrings]

[…] But when I try to use the command, it looks like this (var_dump):

@sardjn You're trying to access some temporary files that are created and also removed by the project itself, this is why the message tells you that dot can't open /tmp/graphvizDEdKjJ (the file doesn't exist). It seems like you have graphviz successfully installed, otherwise the message would tell you that it doesn't know the dot command, you just can't access these unknown files.