問題

Sample.create({name: "hoge", icon: File::open('db/dummy-001.png')})

rails aborted!
Errno::EXDEV: Invalid cross-device link @ rb_file_s_link - (db/dummy-001.png, /tmp/7408f7ac8f26bae8efad1f94360df7e420200514-12545-30ex00.png)
/work/vendor/bundle/ruby/2.4.0/gems/paperclip-6.1.0/lib/paperclip/io_adapters/abstract_adapter.rb:62:in `link_or_copy_file'
/work/vendor/bundle/ruby/2.4.0/gems/paperclip-6.1.0/lib/paperclip/io_adapters/abstract_adapter.rb:55:in `copy_to_tempfile'
/work/vendor/bundle/ruby/2.4.0/gems/paperclip-6.1.0/lib/paperclip/io_adapters/file_adapter.rb:21:in `cache_current_values'
/work/vendor/bundle/ruby/2.4.0/gems/paperclip-6.1.0/lib/paperclip/io_adapters/file_adapter.rb:11:in `initialize'
/work/vendor/bundle/ruby/2.4.0/gems/paperclip-6.1.0/lib/paperclip/io_adapters/registry.rb:33:in `new'
/work/vendor/bundle/ruby/2.4.0/gems/paperclip-6.1.0/lib/paperclip/io_adapters/registry.rb:33:in `for'
/work/vendor/bundle/ruby/2.4.0/gems/paperclip-6.1.0/lib/paperclip/attachment.rb:100:in `assign'
/work/vendor/bundle/ruby/2.4.0/gems/paperclip-6.1.0/lib/paperclip/has_attached_file.rb:66:in `block in define_setter'
/work/vendor/bundle/ruby/2.4.0/gems/activemodel-5.2.1/lib/active_model/attribute_assignment.rb:51:in `public_send'
/work/vendor/bundle/ruby/2.4.0/gems/activemodel-5.2.1/lib/active_model/attribute_assignment.rb:51:in `_assign_attribute'
/work/vendor/bundle/ruby/2.4.0/gems/activemodel-5.2.1/lib/active_model/attribute_assignment.rb:44:in `block in _assign_attributes'
/work/vendor/bundle/ruby/2.4.0/gems/activemodel-5.2.1/lib/active_model/attribute_assignment.rb:43:in `each'
/work/vendor/bundle/ruby/2.4.0/gems/activemodel-5.2.1/lib/active_model/attribute_assignment.rb:43:in `_assign_attributes'
/work/vendor/bundle/ruby/2.4.0/gems/activerecord-5.2.1/lib/active_record/attribute_assignment.rb:23:in `_assign_attributes'
/work/vendor/bundle/ruby/2.4.0/gems/activemodel-5.2.1/lib/active_model/attribute_assignment.rb:35:in `assign_attributes'
/work/vendor/bundle/ruby/2.4.0/gems/activerecord-5.2.1/lib/active_record/core.rb:314:in `initialize'
/work/vendor/bundle/ruby/2.4.0/gems/activerecord-5.2.1/lib/active_record/inheritance.rb:66:in `new'
/work/vendor/bundle/ruby/2.4.0/gems/activerecord-5.2.1/lib/active_record/inheritance.rb:66:in `new'
/work/vendor/bundle/ruby/2.4.0/gems/activerecord-5.2.1/lib/active_record/persistence.rb:35:in `create'
/work/db/seeds.rb:41:in `block in <main>'
/work/db/seeds.rb:41:in `map'
/work/db/seeds.rb:41:in `<main>'
/work/vendor/bundle/ruby/2.4.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:50:in `load'
/work/vendor/bundle/ruby/2.4.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:50:in `load'
/work/vendor/bundle/ruby/2.4.0/gems/activesupport-5.2.1/lib/active_support/dependencies.rb:281:in `block in load'
/work/vendor/bundle/ruby/2.4.0/gems/activesupport-5.2.1/lib/active_support/dependencies.rb:253:in `load_dependency'
/work/vendor/bundle/ruby/2.4.0/gems/activesupport-5.2.1/lib/active_support/dependencies.rb:281:in `load'
/work/vendor/bundle/ruby/2.4.0/gems/railties-5.2.1/lib/rails/engine.rb:551:in `load_seed'
/work/vendor/bundle/ruby/2.4.0/gems/activerecord-5.2.1/lib/active_record/tasks/database_tasks.rb:281:in `load_seed'
/work/vendor/bundle/ruby/2.4.0/gems/activerecord-5.2.1/lib/active_record/railties/databases.rake:194:in `block (2 levels) in <main>'
/work/vendor/bundle/ruby/2.4.0/gems/railties-5.2.1/lib/rails/commands/rake/rake_command.rb:23:in `block in perform'
/work/vendor/bundle/ruby/2.4.0/gems/railties-5.2.1/lib/rails/commands/rake/rake_command.rb:20:in `perform'
/work/vendor/bundle/ruby/2.4.0/gems/railties-5.2.1/lib/rails/command.rb:48:in `invoke'
/work/vendor/bundle/ruby/2.4.0/gems/railties-5.2.1/lib/rails/commands.rb:18:in `<main>'
/work/vendor/bundle/ruby/2.4.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:21:in `require'
/work/vendor/bundle/ruby/2.4.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:21:in `block in require_with_bootsnap_lfi'
/work/vendor/bundle/ruby/2.4.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/loaded_features_index.rb:65:in `register'
/work/vendor/bundle/ruby/2.4.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:20:in `require_with_bootsnap_lfi'
/work/vendor/bundle/ruby/2.4.0/gems/bootsnap-1.3.2/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:29:in `require'
/work/vendor/bundle/ruby/2.4.0/gems/activesupport-5.2.1/lib/active_support/dependencies.rb:287:in `block in require'
/work/vendor/bundle/ruby/2.4.0/gems/activesupport-5.2.1/lib/active_support/dependencies.rb:253:in `load_dependency'
/work/vendor/bundle/ruby/2.4.0/gems/activesupport-5.2.1/lib/active_support/dependencies.rb:287:in `require'
bin/rails:4:in `<top (required)>'
/usr/local/bundle/bin/bundle:23:in `load'
/usr/local/bundle/bin/bundle:23:in `<main>'
Tasks: TOP => db:seed
(See full trace by running task with --trace)
make: *** [seed] Error 1

解決

vendor 配下が何らかの理由で壊れていたようです...。

$ rm -rf vendor/
$ bundle install --path vendor/bundle