1)
$ apt-cache depends -i libgnutls26
libgnutls26
  Depends: libc6
  Depends: libgcrypt11
  Depends: libp11-kit0
  Depends: libtasn1-6
  Depends: zlib1g
  PreDepends: multiarch-support

================================
2)
$ apt-get install --dry-run libgnutls26
NOTE: This is only a simulation!
      apt-get needs root privileges for real execution.
      Keep also in mind that locking is deactivated,
      so don't depend on the relevance to the real current situation!
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following package was automatically installed and is no longer required:
  ruby-safe-yaml
Use 'apt-get autoremove' to remove it.
The following extra packages will be installed:
  libgnutls-openssl27 <===============
Suggested packages:
  gnutls-bin
The following packages will be upgraded:
  libgnutls-openssl27 libgnutls26 <===============
2 upgraded, 0 newly installed, 0 to remove and 202 not upgraded.
Inst libgnutls-openssl27 [2.12.23-12ubuntu2.4] (2.12.23-12ubuntu2.5 Ubuntu:14.04/trusty-updates [amd64]) []
Inst libgnutls26 [2.12.23-12ubuntu2.4] (2.12.23-12ubuntu2.5 Ubuntu:14.04/trusty-updates [amd64])
Conf libgnutls26 (2.12.23-12ubuntu2.5 Ubuntu:14.04/trusty-updates [amd64])
Conf libgnutls-openssl27 (2.12.23-12ubuntu2.5 Ubuntu:14.04/trusty-updates [amd64])