Comment 0 for bug 1429529

[Description]
On 14.04.2 aptitude/APT determinates non-LTSEnablementStack Mesa packages instead of *lts-utopic pendants as dependencies. This leads to unsolvable conflicts with the already installed *lts-utopic packages.

[Test Case]
[a] libgles2-mesa (10.1.3-0ubuntu0.3) instead of libgles2-mesa-lts-utopic (10.3.2-0ubuntu1~trusty2)
$ sudo aptitude install qtbase5-dev
The following NEW packages will be installed:
  libglapi-mesa{a} libgles2-mesa{ab} libgles2-mesa-dev{a} libglu1-mesa-dev{a} libqt5concurrent5{a} libqt5opengl5-dev{a} qt5-qmake{a}
  qtbase5-dev qtbase5-dev-tools{a}
0 packages upgraded, 9 newly installed, 0 to remove and 0 not upgraded.
Need to get 4,439 kB of archives. After unpacking 27.9 MB will be used.
The following packages have unmet dependencies:
 xserver-xorg-lts-utopic : Conflicts: libglapi-mesa (>= 0~) but 10.1.3-0ubuntu0.3 is to be installed.
                           Conflicts: libgles2-mesa (>= 0~) but 10.1.3-0ubuntu0.3 is to be installed.
 libgles2-mesa : Conflicts: libgles2 which is a virtual package.
 libglapi-mesa-lts-utopic : Conflicts: libglapi-mesa but 10.1.3-0ubuntu0.3 is to be installed.
 libgles2-mesa-lts-utopic : Conflicts: libgles2 which is a virtual package.
                            Conflicts: libgles2-mesa but 10.1.3-0ubuntu0.3 is to be installed.

libglapi-mesa conflicts due to libgles2-mesa having a dependency on libglapi-mesa (= 10.1.3-0ubuntu0.3).

[b] libgl1-mesa-dev (10.1.3-0ubuntu0.3) instead of libgl1-mesa-lts-utopic (10.3.2-0ubuntu1~trusty2)
$ sudo aptitude install freeglut3-dev
The following NEW packages will be installed:
  freeglut3{a} freeglut3-dev libdrm-dev{a} libgl1-mesa-dev{a} libgl1-mesa-dri{a} libgl1-mesa-glx{ab} libglapi-mesa{a} libglu1-mesa-dev{a}
  libice-dev{a} libllvm3.4{a} libpthread-stubs0-dev{a} libsm-dev{a} libx11-dev{a} libx11-doc{a} libx11-xcb-dev{a} libxau-dev{a}
  libxcb-dri2-0-dev{a} libxcb-dri3-dev{a} libxcb-glx0-dev{a} libxcb-present-dev{a} libxcb-randr0-dev{a} libxcb-render0-dev{a}
  libxcb-shape0-dev{a} libxcb-sync-dev{a} libxcb-xfixes0-dev{a} libxcb1-dev{a} libxdamage-dev{a} libxdmcp-dev{a} libxext-dev{a}
  libxfixes-dev{a} libxshmfence-dev{a} libxt-dev{a} libxxf86vm-dev{a} mesa-common-dev{a} x11proto-core-dev{a} x11proto-damage-dev{a}
  x11proto-dri2-dev{a} x11proto-fixes-dev{a} x11proto-gl-dev{a} x11proto-input-dev{a} x11proto-kb-dev{a} x11proto-xext-dev{a}
  x11proto-xf86vidmode-dev{a} xorg-sgml-doctools{a} xtrans-dev{a}
0 packages upgraded, 45 newly installed, 0 to remove and 68 not upgraded.
Need to get 16.6 MB of archives. After unpacking 88.2 MB will be used.
The following packages have unmet dependencies:
 libgl1-mesa-dri-lts-utopic : Conflicts: libgl1-mesa-dri but 10.1.3-0ubuntu0.3 is to be installed.
 libgl1-mesa-glx-lts-utopic : Conflicts: libgl1 which is a virtual package.
                              Conflicts: libgl1-mesa-glx but 10.1.3-0ubuntu0.3 is to be installed.
 xserver-xorg-lts-utopic : Conflicts: libgl1-mesa-dri (>= 0~) but 10.1.3-0ubuntu0.3 is to be installed.
                           Conflicts: libgl1-mesa-glx (>= 0~) but 10.1.3-0ubuntu0.3 is to be installed.
                           Conflicts: libglapi-mesa (>= 0~) but 10.1.3-0ubuntu0.3 is to be installed.
 libgl1-mesa-glx : Conflicts: libgl1 which is a virtual package.
 libglapi-mesa-lts-utopic : Conflicts: libglapi-mesa but 10.1.3-0ubuntu0.3 is to be installed.

[Workaround]
[a]
$ sudo aptitude install qtbase5-dev libgles2-mesa-lts-utopic

[b]
$ sudo aptitude install -s freeglut3-dev libgl1-mesa-dev-lts-utopic