N900 PREENV下載失敗

我用XT下載的
顯示
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
preenv: Depends: libgles1-sgx-img but it is not installable
E: Broken packages
請幫忙解答