Data inheritance not working

I've been trying out the changes from https://github.com/drupal-pattern-lab/patternengine-php-twig/pull/1 and am struggling to get data inheritance to work. According to @EvanLovely in https://github.com/pattern-lab/patternengine-php-twig/issues/36#issuecomment-322295048 this should be working.

I'm using a fork of Phase2's pattern lab starter and this is my composer.json:

{
  "name": "phase2/pattern-lab-starter",
  "description": "Phase2 Pattern Lab for Drupal based on Pattern Lab's Drupal Edition",
  "keywords": [
    "pattern lab",
    "drupal"
  ],
  "homepage": "https://github.com/phase2/pattern-lab-starter",
  "license": "GPL-2.0+",
  "authors": [
    {
      "name": "Evan Lovely",
      "role": "Lead Developer"
    }
  ],
  "support": {
    "issues": "https://github.com/phase2/pattern-lab-starter/issues"
  },
  "autoload": {
    "psr-0": {
      "PatternLab": "core/src/"
    }
  },
  "repositories": [
    {
      "type": "vcs",
      "url": "https://github.com/drupal-pattern-lab/patternlab-php-core.git"
    }
  ],
  "require": {
    "php": ">=5.5.9",
    "pattern-lab/core": "^2.8.0",
    "pattern-lab/patternengine-twig": "^2.0.0",
    "pattern-lab/styleguidekit-twig-default": "^3.0.0",
    "pattern-lab/drupal-twig-components": "^2.0.0",
    "pattern-lab/plugin-faker": "^2.0",
    "evanlovely/plugin-twig-namespaces": "^1.0",
    "aleksip/plugin-data-transform": "^1.1"
  },
  "scripts": {
    "post-install-cmd": [
      "PatternLab\\Installer::postInstallCmd"
    ],
    "post-update-cmd": [
      "PatternLab\\Installer::postUpdateCmd"
    ],
    "post-root-package-install": [
      "PatternLab\\Installer::setProjectInstall",
      "PatternLab\\Installer::getSuggestedStarterKits",
      "PatternLab\\Installer::getConfigOverrides"
    ],
    "post-package-install": [
      "PatternLab\\Installer::postPackageInstall"
    ],
    "post-package-update": [
      "PatternLab\\Installer::postPackageUpdate"
    ],
    "pre-package-uninstall": [
      "PatternLab\\Installer::prePackageUninstall"
    ]
  },
  "extra": {
    "patternlab": {
    }
  }
}

It might be entirely possible that I need to install other forked repos but its not clear to me what I need.

My understanding is that aleksip/plugin-data-transform should provide the data inheritance.

My simple test scenario is:

Parent template:

<div class="paragraph-text-only__text-long">
  {% include "@atoms/fields/text-long/text-long.twig" %}
</div>

Included template (text-long.twig):

{{ content }}

The included template also has some associated data in text-long.json:

{
  "content": "Some test content"
}

When I view the parent template I see errors:

Notice: Array to string conversion in /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/vendor/twig/twig/lib/Twig/Environment.php(462) : eval()'d code on line 19 Call Stack: 0.0002 263464 1. {main}() /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/core/console:0 0.0393 4339136 2. PatternLab\Console::run() /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/core/console:46 0.0416 4572504 3. PatternLab\Console\Commands\GenerateCommand->run() /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/vendor/pattern-lab/core/src/PatternLab/Console.php:91 0.0588 6514696 4. PatternLab\Generator->generate() /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/vendor/pattern-lab/core/src/PatternLab/Console/Commands/GenerateCommand.php:42 0.0749 6888824 5. PatternLab\PatternData::gather() /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/vendor/pattern-lab/core/src/PatternLab/Generator.php:69 0.1822 10144408 6. PatternLab\PatternData\Helpers\PatternCodeHelper->run() /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/vendor/pattern-lab/core/src/PatternLab/PatternData.php:209 3.0459 41953616 7. PatternLab\PatternEngine\Twig\Loaders\PatternLoader->render() /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/vendor/pattern-lab/core/src/PatternLab/PatternData/Helpers/PatternCodeHelper.php:89 3.0459 41953616 8. Twig_Environment->render() /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/vendor/pattern-lab/patternengine-twig/src/PatternLab/PatternEngine/Twig/Loaders/PatternLoader.php:119 3.1064 43015848 9. Twig_Template->render() /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/vendor/twig/twig/lib/Twig/Environment.php:362 3.1064 43032560 10. Twig_Template->display() /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/vendor/twig/twig/lib/Twig/Template.php:411 3.1064 43033024 11. Twig_Template->displayWithErrorHandling() /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/vendor/twig/twig/lib/Twig/Template.php:403 3.1064 43033096 12. __TwigTemplate_ffe61fee2246b15f94ee22ff8815e151d63c4190ab0da22d17d478f808ff4e6d->doDisplay() /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/vendor/twig/twig/lib/Twig/Template.php:432 3.1072 43875792 13. Twig_Template->display() /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/vendor/twig/twig/lib/Twig/Environment.php(462) : eval()'d code:33 3.1072 43876064 14. Twig_Template->displayWithErrorHandling() /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/vendor/twig/twig/lib/Twig/Template.php:403 3.1072 43876064 15. __TwigTemplate_3275ef305a7d7efaddc7a0078b511bbf2e63fb899408c45405c3479f2c187593->doDisplay() /Users/tanc/Sites/l.install_profile/gitroot/web/themes/custom/site_theme/pattern-lab/vendor/twig/twig/lib/Twig/Template.php:432 Array

Is there anything I'm missing? Any advice on where to start looking?

drupal-pattern-lab / patternengine-php-twig

Data inheritance not working #4