Exception thrown by responsive srcset images when the image is not yet in the file system (such as with Stage File Proxy)

Did you try it with the latest dev version when you filed this issue?
#2822429: template_preprocess_responsive_image() does unnecessary IO by creating Image objects was committed on Nov 1st 2016, and it seems it might have fixed the issue. I tried this using the latest git checkout today and couldn't reproduce the error.

1. I installed the site using the standard install profile.
2. I enabled Responsive Image and Stage File Proxy.
3. I configured the responsive image style:
   

   langcode: en
   status: true
   dependencies:
     config:
       - image.style.max_1300x1300
       - image.style.max_2600x2600
       - image.style.max_325x325
       - image.style.max_650x650
   id: break_it
   label: 'Break it'
   image_style_mappings:
     -
       breakpoint_id: responsive_image.viewport_sizing
       multiplier: 1x
       image_mapping_type: sizes
       image_mapping:
         sizes: 100vw
         sizes_image_styles:
           - max_1300x1300
           - max_2600x2600
           - max_325x325
           - max_650x650
   breakpoint_group: responsive_image
   fallback_image_style: '_empty image_'
   

4. I configured stage file proxy (setting the proxy address to the same site but under sites/default/files2 instead of sites/default/files).
5. I uploaded a file in an article node.
6. I moved the directory 2016-12 from sites/default/files to sites/default/files2.
7. I removed the directory sites/default/files/styles.
8. I loaded the article page and didn't get an Exception.

Reopening because I am still able to produce this issue. When the source file for a responsive image style is missing from the local file system, Drupal is unable to determine the width/height of the image and thus, the exception is thrown.

For example, in the following snippet, if the file referenced by $media_entity->field_media_image is missing, the page attempting to include it will bomb.

$media = [
  '#theme' => 'responsive_image',
  '#responsive_image_style_id' => 'content_image',
  '#uri' => $media_entity->field_media_image->entity->getFileUri(),
  '#attributes' => [
    'alt' => $media_entity->field_media_image->alt,
  ],
]; 

We have been able to work around this by forcing a width/height value, like so:

$media = [
  '#theme' => 'responsive_image',
  '#responsive_image_style_id' => 'content_image',
  '#uri' => $media_entity->field_media_image->entity->getFileUri(),
  '#attributes' => [
    'alt' => $media_entity->field_media_image->alt,
  ],
  '#height' => 540,
  '#width' => 960,
]; 

When SFP has had a chance to pull down the source image, for example when visiting the entity's view/edit pages, the page renders without issue. Presumably, because the width/height have been reliably determined within _responsive_image_build_source_attributes().

I'm unsure as to the best path forward, but my gut says that if an image asset is missing from the local filesystem, the responsive image module should simply render a broken image, versus throwing an exception that brings down the entire page.

Still in issue in 8.4 so updating version.

I created a sister issue to try and solve this in Stage File Proxy as well: #2922292: Support responsive images, because it's not clear who should really be responsible for making this work.

I think it's a little harsh for core to throw an uncaught exception when this happens though. As a site owner, do you really want your site to completely tank when an image file is missing on your server for whatever reason? Wouldn't you rather just a broken image appear?

A more reasonable approach may to log the error & output the image w/o srcset attribute set at all. Instead it would just output the fallback image style.

Here's a patch that removes the exception and replaces it with an error in the logs.

Patch tested and so far appears to be working. We just deployed this out to a production site and will report back if we find any issues. Thank you @bkosborne!

It makes sense to make not throw the exception and log the error instead, however I think we should add test coverage here.

Still a problem here, on 8.6.1 with SFP and flysystem_s3.

#7 fixed the fatal on missing images for me on core 8.9.1.

Same issue with Drupal 8.9.15

LogicException: Could not determine image width for 'public://.....jpg' using image style with ID: max_1300x1300. This image style can not be used for a responsive image style mapping using the 'sizes' attribute. in _responsive_image_build_source_attributes() (line 434 of web\core\modules\responsive_image\responsive_image.module).

This patch resolves the issue for us as well! RTBC +1

Rerolled patch addresses coding standards error.

Hi, Great! This Patch resolved mij WSOD on homepage D8. Thanks. And please get it in next release, so others don't have this problem.
Thanks for building and rerolling! Greetings, Martijn

Patch at #22 works for me

Patch #22 worked for me. RTBC +1

Tested patch with Drupal 9.3.9 and PHP 8.0.16 using Stage File Proxy 8.x-1.2

We still need to address #10 and add tests to this issue so +1 to keep it on Needs Work

I tried myself to add some tests for the patch, but the problem is that the code to be tested is inside the responsive_image.module file and I don't know yet how to test code inside *.module files.

RTBC +1 this resolved the problem for us when using proxy file module.

Rerolled patch

This issue occurs with the s3fs module as well and I can confirm that the patch correctly handles the error for that contrib module as well. Updating the issue summary to reflect that a core fix would solve the issue for more than just stage file proxy.

Would something like this need tests? The patch basically shifts the error to the error logs rather than disrupting page render. That seems reasonable.

This patch fixes the fatal error, which is great, but it has downstream PHP warning/notice issues as the underlying responsive image code expects certain metadata (width, height) to always be set.

Warning: Undefined array key "width" in template_preprocess_responsive_image() (line 209 of core/modules/responsive_image/responsive_image.module).
template_preprocess_responsive_image(Array, 'responsive_image', Array)

The patch in #35 fixes the issue for me with no images and with Stage File Proxy on Drupal 10.4.3.

Leaving as Needs Work though for the comments in #37.

port patch for 11.3.1

I added a test that fails without the patch.

Can we turn the test to a kernel.

In an effort to go more kernel can we convert that please.