yocto_sdk有很多警告：软件包不可安装

我正在使用yocto 2.6（thud）定制我的linux映像，现在我可以使用bitbake用我自己的应用程序生成映像，映像在主板上运行良好

现在，我正在尝试填充sdk，我做到了：

bitbake dey-image -c populate_sdk

然后我有很多警告，比如

The following packages have unmet dependencies:
 apt-dev : Depends: apt (= 1.2.24-r0.1) but it is not going to be installed
           Recommends: bash-dev
           Recommends: libcurl-dev but it is not installable
 hwmoniter-dev : Depends: hwmoniter (= git-r0.7) but it is not going to be installed
                 Recommends: libmosquitto1-dev but it is not installable
E: Unable to correct problems, you have held broken packages.
Summary: There was 1 WARNING message shown.

似乎

populate_sdk

终于成功了，出现了警告，sdk（*.sh）已经生成并可以安装，但是我找不到我认为存在的许多头文件

那么这些警告意味着什么呢？“不安装”和“不可安装”之间有什么区别？如何修复这些警告

谢谢