7 files declare their use of BreadcrumbBuilderInterface in Drupal 8

BookBreadcrumbBuilder.php in core/modules/book/src/BookBreadcrumbBuilder.php

CommentBreadcrumbBuilder.php in core/modules/comment/src/CommentBreadcrumbBuilder.php

ForumBreadcrumbBuilderBase.php in core/modules/forum/src/Breadcrumb/ForumBreadcrumbBuilderBase.php

HelpBreadcrumbBuilder.php in core/modules/help_topics/src/HelpBreadcrumbBuilder.php

PathBasedBreadcrumbBuilder.php in core/modules/system/src/PathBasedBreadcrumbBuilder.php

SystemBreadcrumbBlock.php in core/modules/system/src/Plugin/Block/SystemBreadcrumbBlock.php

TermBreadcrumbBuilder.php in core/modules/taxonomy/src/TermBreadcrumbBuilder.php