您的捆绑包被锁定到 imimemagic (0.3.5) ，但是在 Gemfile 中列出的任何源代码中都找不到该版本

今天我试图为我的 Rails6.1.0构建一个带有活动存储的 docker，我得到了以下错误:

Your bundle is locked to mimemagic (0.3.5), but that version could not be found in any of the sources listed in your Gemfile. If you haven't changed sources, that means the author of mimemagic (0.3.5) has removed it. You'll need to update your
bundle to a version other than mimemagic (0.3.5) that hasn't been removed in order to install.

现在我试着安装这个模仿装置

 gem install mimemagic -v 0.3.5

我得到了以下错误:

ERROR:  Could not find a valid gem 'mimemagic' (= 0.3.5) in any repository
ERROR:  Possible alternatives: mimemagic

宝石好像不见了，有人能解释一下吗？

解决这个问题的办法是什么？