当我升级或安装时，出现此错误。
srikanth@btp8sa42:~/projects/raff$ sudo apt-get upgrade
[sudo] password for srikanth:
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt-get -f install' to correct these.
The following packages have unmet dependencies:
libcurl3-gnutls : Depends: libc6 (>= 2.15) but 2.13-20ubuntu5.3 is installed
Depends: libgnutls26 (>= 2.12.6.1-0) but 2.10.5-1ubuntu3.2 is installed
Depends: libgssapi-krb5-2 (>= 1.10+dfsg~) but 1.9.1+dfsg-1ubuntu2.3 is installed
libp11-kit0 : Depends: libc6 (>= 2.14) but 2.13-20ubuntu5.3 is installed
E: Unmet dependencies. Try using -f.
当我执行“apt-get -f install”时
srikanth@btp8sa42:~/projects/raff$ sudo apt-get -f install
Reading package lists... Done
Building dependency tree
Reading state information... Done
Correcting dependencies... failed.
The following packages have unmet dependencies:
libcurl3-gnutls : Depends: libc6 (>= 2.15) but 2.13-20ubuntu5.3 is installed
Depends: libgnutls26 (>= 2.12.6.1-0) but 2.10.5-1ubuntu3.2 is installed
Depends: libgssapi-krb5-2 (>= 1.10+dfsg~) but 1.9.1+dfsg-1ubuntu2.3 is installed
libp11-kit0 : Depends: libc6 (>= 2.14) but 2.13-20ubuntu5.3 is installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.
E: Unable to correct dependencies
我怎样才能解决这个问题？