diff --git a/pavelib/utils/envs.py b/pavelib/utils/envs.py
index d2cdd4a77d7a..7dc9870fbdea 100644
--- a/pavelib/utils/envs.py
+++ b/pavelib/utils/envs.py
@@ -88,15 +88,19 @@ class Env:
         KARMA_BROWSER = 'FirefoxNoUpdates'
 
     # Files used to run each of the js test suites
-    # TODO:  Store this as a dict. Order seems to matter for some
-    # reason. See issue TE-415.
+    # TODO: We have [temporarily disabled] the three Webpack-based tests suites. They have been silently
+    #       broken for a long time; after noticing they were broken, we added the DieHardPlugin to
+    #       webpack.common.config.js to prevent future silent breakage, but have not yet been able to
+    #       fix and re-enable the suites. Note that the LMS suite is all Webpack-based even though it's
+    #       not in the name.
+    #       Issue: https://github.com/openedx/edx-platform/issues/35956
     KARMA_CONFIG_FILES = [
         REPO_ROOT / 'cms/static/karma_cms.conf.js',
         REPO_ROOT / 'cms/static/karma_cms_squire.conf.js',
-        REPO_ROOT / 'cms/static/karma_cms_webpack.conf.js',
-        REPO_ROOT / 'lms/static/karma_lms.conf.js',
+        ## [temporarily disabled] REPO_ROOT / 'cms/static/karma_cms_webpack.conf.js',
+        ## [temporarily disabled] REPO_ROOT / 'lms/static/karma_lms.conf.js',
         REPO_ROOT / 'xmodule/js/karma_xmodule.conf.js',
-        REPO_ROOT / 'xmodule/js/karma_xmodule_webpack.conf.js',
+        ## [temporarily disabled] REPO_ROOT / 'xmodule/js/karma_xmodule_webpack.conf.js',
         REPO_ROOT / 'common/static/karma_common.conf.js',
         REPO_ROOT / 'common/static/karma_common_requirejs.conf.js',
     ]
@@ -104,10 +108,10 @@ class Env:
     JS_TEST_ID_KEYS = [
         'cms',
         'cms-squire',
-        'cms-webpack',
-        'lms',
+        ## [temporarily-disabled] 'cms-webpack',
+        ## [temporarily-disabled] 'lms',
         'xmodule',
-        'xmodule-webpack',
+        ## [temporarily-disabled] 'xmodule-webpack',
         'common',
         'common-requirejs',
         'jest-snapshot'
diff --git a/webpack.common.config.js b/webpack.common.config.js
index de8b545c978b..c9b69eef4292 100644
--- a/webpack.common.config.js
+++ b/webpack.common.config.js
@@ -26,6 +26,27 @@ var defineFooter = new RegExp('(' + defineCallFooter.source + ')|('
 var staticRootLms = process.env.STATIC_ROOT_LMS || './test_root/staticfiles';
 var staticRootCms = process.env.STATIC_ROOT_CMS || (staticRootLms + '/studio');
 
+class DieHardPlugin {
+  /* A small plugin which ensures that if Webpack fails, it causes the surrounding process to fail
+   * as well. This helps us prevent JavaScript CI from "false passing" upon build failures--that is,
+   * we want to avoid having another situation where the Webpack build breaks under Karma (our
+   * test runner) but Karma just lets it slide and moves on to the next test suite.
+   *
+   * One would imagine that this would be Webpack's default behavior (and maybe it is?) but,
+   * regardless, karma-webpack does not seem to consider Webpack build failures to be fatal errors
+   * without this plugin. We don't fully understand it, but this is good enough given that we plan
+   * to remove all JS in this repo soon (https://github.com/openedx/edx-platform/issues/31620).
+   *
+   * Inpsired by: https://github.com/codymikol/karma-webpack/issues/49#issuecomment-842682050
+   */
+  apply(compiler) {
+    compiler.hooks.failed.tap('DieHardPlugin', (error) => {
+      console.error(error);
+      process.exit(1);
+    });
+  }
+}
+
 var workerConfig = function() {
     try {
         return {
@@ -153,6 +174,7 @@ module.exports = Merge.smart({
                 // any other way to declare that dependency.
                 $script: 'scriptjs'
             }),
+            new DieHardPlugin(),
         ],
 
         module: {