Categories call

So what am I doing wrong here - I'm trying to get the category and assign it to a php variable so I can use it for a 'related content' call. The template used is one that purely has the <perch:categories> tags.

    $category = perch_content_custom('Analysis', array(
        'page' => '/topics.php',
        'template' => '_just_category.html',
        'filter' => 'slug',
        'match' => 'eq',
        'value' => perch_get('s'),
        'count' => 1
    ));

This returns the category correctly and prints it, but doesn't assign the value to the variable $category. If I run the following instead

    $category = perch_content_custom('Analysis', array(
        'page' => '/topics.php',
        'template' => '_just_category.html',
        'filter' => 'slug',
        'match' => 'eq',
        'value' => perch_get('s'),
        'count' => 1
    ), true);

it completely disappears from the page. It doesn't completely die - the footer is still there. But everything related to this code and the subsequent perch_content_custom calls using the variable do not print.

In the case of the first one, the variable contains nothing.

Nothing jumps out at me.

    <?php
        //get category and put it into a variable
        $category = perch_content_custom('Analysis', array(
        'page' => '/topics.php',
        'template' => '_just_category.html',
        'filter' => 'slug',
        'match' => 'eq',
        'value' => perch_get('s'),
        'count' => 1
    ),true);

    ?>

produces the following:

SELECT * FROM perch2_categories ORDER BY catTreePosition ASC
SELECT * FROM ( SELECT idx.itemID, c.regionID, idx.pageID, c.itemJSON, idx2.indexValue as sortval FROM perch2_content_index idx 
JOIN perch2_content_items c ON idx.itemID=c.itemID AND idx.itemRev=c.itemRev AND idx.regionID=c.regionID
JOIN perch2_content_index idx2 ON idx.itemID=idx2.itemID AND idx.itemRev=idx2.itemRev AND idx2.indexKey='_order' WHERE ((idx.regionID='6' AND idx.itemRev='47')) AND ((idx.indexKey='slug' AND idx.indexValue='how-to-get-to-grips-with-deforestation-risks')) AND idx.itemID=idx2.itemID AND idx.itemRev=idx2.itemRev
) as tbl GROUP BY itemID ORDER BY sortval ASC LIMIT 0, 1
Using template: /templates/content/_just_category.html

Then the subsequent call:

    $results_found = false;
    //use that category to get related features
    $result = perch_content_custom('Analysis', array(
        'page' => '/topics.php',
        'template' => '_secondary_listing.html',
        'filter' => 'slug',
        'match' => 'neq',
        'value' => perch_get('s'),
        'count' => 2,
        'category' => "analysis/$category"
        ),true);

    if ($result){
        ?>
    <section class="related_stories">
    <h2>Related content</h2>
    <?php
        echo $result;
        $results_found = true;
    ?>

produces this:

SELECT * FROM perch2_categories ORDER BY catTreePosition ASC
SELECT idx.itemID FROM perch2_content_index idx JOIN perch2_content_items c ON idx.itemID=c.itemID AND idx.itemRev=c.itemRev AND idx.regionID=c.regionID WHERE ((idx.regionID='6' AND idx.itemRev='47')) AND (idx.indexKey='_category' AND idx.indexValue LIKE 'analysis/\n Deforestation\n%')
SELECT * FROM ( SELECT idx.itemID, c.regionID, idx.pageID, c.itemJSON, idx2.indexValue as sortval FROM perch2_content_index idx 
JOIN perch2_content_items c ON idx.itemID=c.itemID AND idx.itemRev=c.itemRev AND idx.regionID=c.regionID
JOIN perch2_content_index idx2 ON idx.itemID=idx2.itemID AND idx.itemRev=idx2.itemRev AND idx2.indexKey='_order' WHERE ((idx.regionID='6' AND idx.itemRev='47')) AND idx.itemID IN (NULL) AND ((idx.indexKey='slug' AND idx.indexValue != 'how-to-get-to-grips-with-deforestation-risks')) AND idx.itemID=idx2.itemID AND idx.itemRev=idx2.itemRev
) as tbl GROUP BY itemID ORDER BY sortval ASC LIMIT 0, 2
Using template: /templates/content/_secondary_listing.html

Thanks. I hadn't noticed that I needed to pull the slug, not the title - and I don't know why the variable was coming in with new line characters, but I've used trim() to strip them off and now it works.