Module Description not visible when it is not compatible.

How about this?

Rerolled

Adapt to screenshot:

from comment #2

+++ b/core/modules/system/src/Form/ModulesListForm.php
@@ -369,7 +369,8 @@ protected function buildRow(array $modules, Extension $module, $distribution) {
+      $row['description']['#prefix'] = $row['description']['#markup'] . '<br>';
+      $row['description']['#markup'] = '<strong>' . $status . '</strong>';

Why do we add html markup here? Original patch did not.

I added the HTML markup to adapt to the screenshot posted in comment #2. Otherwise, the description just comes before the error. How else can this be done?

It is still not clear to me why we didn't need markup in #2 and we need it on #6. If it is true, this should be in a template or something I guess.
Also, we would need a test.

$row['description']['#theme'] ='system_modules_incompatible'; was removed because 0 matches throughout Drupal.

Without markup:

With markup:

It is a bad practice to add HTML tags in-line like that. I think we should create element in $row (w/ $status string) and then theming it with 'system_modules_details'.
Also I'm not sure it's worth to prepend description before collapsed notice. I mean that warning is more important for user. So I suggest to display a error message first.

The best way in my opinion show a description with other secondary module information. I have created a patch for it.

What do you think?

Added just test

Had error while copy/pasting from my other code-base in above patch. Corrected test patch included in this comment.

This patch contains patch from #11 and test update to ModulesListFormWebTest.

Tested patch in message #17 on Drupal 8.0.x

Patch installed cleanly with no errors.

D8 module test

Installed a contrib module (Weight)
Module appeared in the module list at /admin/modules
Modified the yml file, changed CORE and DESCRIPTION
Checked the module list at /admin/modules and the module showed as incompatible, and showed updated core and description
Enabled Test module, and ran ModulesListFormWebTest
Results
27 passes, 0 fails, 0 exceptions, 6 debug messages

D8 module test w/o yml file

Installed a D8 module that did contain a .yml file
module was not listed in the module list at /admin/modules

D7 module test

Installed a D7 module (with no .yml file)
module was not listed in the module list at /admin/modules

Patch is functioning as intended.

Adding SprintWeekend2015 tag!

We have tests now, so that tag can be removed. Some minor feedback below, but overall this is looking good to me:

1. +++ b/core/modules/system/system.admin.inc
   @@ -224,6 +224,8 @@ function theme_system_modules_details($variables) {
   +    $incompatible =!empty($module['incompatible']);
   

   Missing space after = sign.

2. +++ b/core/modules/system/system.admin.inc
   @@ -224,6 +224,8 @@ function theme_system_modules_details($variables) {
   +    $title = drupal_render($module['description']);
   
   @@ -236,7 +238,11 @@ function theme_system_modules_details($variables) {
   +        $title = drupal_render($module['incompatible']);
   
   @@ -259,7 +265,7 @@ function theme_system_modules_details($variables) {
   -      '#title' => SafeMarkup::set('<span class="text"> ' . drupal_render($module['description']) . '</span>'),
   +      '#title' => SafeMarkup::set('<span class="text"> ' . $title . '</span>'),
   

   Why not just set $title and drupal_render() once? It seems like with this change we'd end up with unnecessary calls to drupal_render().

About #21-2: It seems, rendered $module['description'] used, even if module is incompatible. So we anyway should call the drupal_render for 'description' element, and we do it only once. Guess, this is look good for me.

$title = drupal_render($module['description']);
...
if ($incompatible) {
$description .= '

' . t('Description: !module-description', array('!module-description' => $title)) . '

';
$title = drupal_render($module['incompatible']);
}

Сorrections of #21-1 are made.

No longer applies.

@cs_shadow, Thank you for reporting this problem. We rely on issue reports like this to improve Drupal core.

I don't know when this was fixed but the description does display when the module is not compatible. Tested on 9.4.x standard install.

Therefore, closing as outdated

Thanks!