Qt5 32-bit runtime libraries not present on 64-bit multiarch linux mint

I have Linux Mint 17.3 (Ubuntu 14.04) 64-bit and I can't get a 32-bit executable which depends on Qt5 to work. If I execute it, it reports

$ ./Program 
./Program: error while loading shared libraries: libQt5Widgets.so.5: cannot open shared object file: No such file or directory

multiarch on the system is enabled:

$ dpkg --print-foreign-architectures
i386

and, even though this seems to be a solution superseded by the debian multiarch approach, ia32-libs is installed.

So I would expect that every 64 bit library in /usr/lib/x86_64-linux-gnu also installs its equivalent 32-bit in /usr/lib/i386-linux-gnu. This seems to work for the Qt4 libraries and many others, as the i386 directory has many items, such as libQtCore.so.4.8.6.

However, as I said I'd like to run a 32-bit executable which depends on Qt5, so I am wondering why I can't find something like libQt5Widgets.so.5.2.1 in the i386-linux-gnu/ directory, even though the corresponding 64-bit shared object with the same name is indeed present in x86_64-linux-gnu/ and the packages seem to be installed:

$ dpkg -l | grep libqt5
ii  libqt5core5a:amd64                          5.2.1+dfsg-1ubuntu14.3                              amd64        Qt 5 core module
ii  libqt5dbus5:amd64                           5.2.1+dfsg-1ubuntu14.3                              amd64        Qt 5 D-Bus module
ii  libqt5gui5:amd64                            5.2.1+dfsg-1ubuntu14.3                              amd64        Qt 5 GUI module
  (...)

I noticed they specify amd64, so I tried to pull in i386 packages but get lots of dependency problems announced that seem not to be resolved automatically, e.g.:

$ sudo apt-get install libqt5widgets5:i386
Reading package lists... Done
Building dependency tree       
Reading state information... Done
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:
 libqt5widgets5:i386 : Depends: libqt5gui5:i386 (>= 5.2.0) but it is not going to be installed or
                                libqt5gui5-gles:i386 (>= 5.2.0) but it is not installable
E: Unable to correct problems, you have held broken packages.

If I try to add the missing dependencies to the install call it pulls me down a rabbit hole of dependencies. So the big two questions:

  • Why wasn't the 32-bit library of Qt5 installed even though multiarch is enabled?
  • How do I install Qt5 32-bit runtime libraries on my 64-bit system?

[Update]

Running sudo apt-get install libqt5widgets5:i386 -o Debug::pkgProblemResolver=yes yields the following:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Starting pkgProblemResolver with broken count: 11
Starting 2 pkgProblemResolver with broken count: 11
Investigating (0) xserver-xorg-core-lts-vivid [ amd64 ] < 2:1.17.1-0ubuntu3.1~trusty1 > ( x11 )
Broken xserver-xorg-core-lts-vivid:amd64 Depends on libegl1-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libegl1-mesa:amd64 1 as a solution to xserver-xorg-core-lts-vivid:amd64 24
  Added libegl1-mesa:amd64 to the remove list
Broken xserver-xorg-core-lts-vivid:amd64 Depends on libegl1 [ amd64 ] < none > ( none )
  Fixing xserver-xorg-core-lts-vivid:amd64 via keep of libegl1-mesa:amd64
Investigating (0) libglapi-mesa-lts-vivid [ amd64 ] < 10.5.9-2ubuntu1~trusty2 > ( libs )
Broken libglapi-mesa-lts-vivid:amd64 Conflicts on libglapi-mesa [ i386 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libglapi-mesa:i386 -3 as a solution to libglapi-mesa-lts-vivid:amd64 5
  Added libglapi-mesa:i386 to the remove list
  Conflicts//Breaks against version 10.1.0-4ubuntu5 for libglapi-mesa but that is not InstVer, ignoring
  Conflicts//Breaks against version 10.3.2-0ubuntu1~trusty2 for libglapi-mesa-lts-utopic but that is not InstVer, ignoring
  Fixing libglapi-mesa-lts-vivid:amd64 via keep of libglapi-mesa:i386
Investigating (0) libcogl15 [ amd64 ] < 1.16.2-1 > ( libs )
Broken libcogl15:amd64 Depends on libegl1-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) (>= 7.8.1)
  Considering libegl1-mesa:amd64 1 as a solution to libcogl15:amd64 4
  Try Installing libegl1-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) before changing libcogl15:amd64
Broken libcogl15:amd64 Depends on libegl1-mesa-drivers [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libegl1-mesa-drivers:amd64 1 as a solution to libcogl15:amd64 4
  Added libegl1-mesa-drivers:amd64 to the remove list
  Fixing libcogl15:amd64 via keep of libegl1-mesa-drivers:amd64
Investigating (0) libwayland-egl1-mesa-lts-vivid [ amd64 ] < 10.5.9-2ubuntu1~trusty2 > ( libs )
Broken libwayland-egl1-mesa-lts-vivid:amd64 Depends on libegl1-mesa-lts-vivid [ amd64 ] < 10.5.9-2ubuntu1~trusty2 > ( libs ) (= 10.5.9-2ubuntu1~trusty2)
  Considering libegl1-mesa-lts-vivid:amd64 2 as a solution to libwayland-egl1-mesa-lts-vivid:amd64 3
  Added libegl1-mesa-lts-vivid:amd64 to the remove list
  Fixing libwayland-egl1-mesa-lts-vivid:amd64 via keep of libegl1-mesa-lts-vivid:amd64
Investigating (0) libqt5gui5 [ amd64 ] < 5.2.1+dfsg-1ubuntu14.3 > ( libs )
Broken libqt5gui5:amd64 Depends on libgles2-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) (>= 7.8.1)
  Considering libgles2-mesa:amd64 0 as a solution to libqt5gui5:amd64 3
  Try Installing libgles2-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) before changing libqt5gui5:amd64
Investigating (0) libegl1-mesa-lts-vivid [ amd64 ] < 10.5.9-2ubuntu1~trusty2 > ( libs )
Broken libegl1-mesa-lts-vivid:amd64 Conflicts on libegl1-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libegl1-mesa:amd64 1 as a solution to libegl1-mesa-lts-vivid:amd64 2
  Added libegl1-mesa:amd64 to the remove list
  Conflicts//Breaks against version 10.1.0-4ubuntu5 for libegl1-mesa but that is not InstVer, ignoring
  Conflicts//Breaks against version 10.3.2-0ubuntu1~trusty2 for libegl1-mesa-lts-utopic but that is not InstVer, ignoring
Broken libegl1-mesa-lts-vivid:amd64 Conflicts on libegl1-mesa [ i386 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libegl1-mesa:i386 -2 as a solution to libegl1-mesa-lts-vivid:amd64 2
  Added libegl1-mesa:i386 to the remove list
  Conflicts//Breaks against version 10.1.0-4ubuntu5 for libegl1-mesa but that is not InstVer, ignoring
  Conflicts//Breaks against version 10.3.2-0ubuntu1~trusty2 for libegl1-mesa-lts-utopic but that is not InstVer, ignoring
Broken libegl1-mesa-lts-vivid:amd64 Conflicts on libegl1-x11 [ amd64 ] < none > ( none )
  Conflicts//Breaks against version 10.3.2-0ubuntu1~trusty2 for libegl1-mesa-lts-utopic but that is not InstVer, ignoring
  Considering libegl1-mesa:amd64 1 as a solution to libegl1-mesa-lts-vivid:amd64 2
  Added libegl1-mesa:amd64 to the remove list
  Conflicts//Breaks against version 10.1.0-4ubuntu5 for libegl1-mesa but that is not InstVer, ignoring
Broken libegl1-mesa-lts-vivid:amd64 Conflicts on libegl1-x11 [ i386 ] < none > ( none )
  Conflicts//Breaks against version 10.3.2-0ubuntu1~trusty2 for libegl1-mesa-lts-utopic but that is not InstVer, ignoring
  Considering libegl1-mesa:i386 -2 as a solution to libegl1-mesa-lts-vivid:amd64 2
  Added libegl1-mesa:i386 to the remove list
  Conflicts//Breaks against version 10.1.0-4ubuntu5 for libegl1-mesa but that is not InstVer, ignoring
  Fixing libegl1-mesa-lts-vivid:amd64 via keep of libegl1-mesa:amd64
  Fixing libegl1-mesa-lts-vivid:amd64 via keep of libegl1-mesa:i386
  Fixing libegl1-mesa-lts-vivid:amd64 via keep of libegl1-mesa:amd64
  Fixing libegl1-mesa-lts-vivid:amd64 via keep of libegl1-mesa:i386
Investigating (0) libglapi-mesa-lts-vivid [ i386 ] < 10.5.9-2ubuntu1~trusty2 > ( libs )
Broken libglapi-mesa-lts-vivid:i386 Conflicts on libglapi-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libglapi-mesa:amd64 -2 as a solution to libglapi-mesa-lts-vivid:i386 0
  Added libglapi-mesa:amd64 to the remove list
  Conflicts//Breaks against version 10.1.0-4ubuntu5 for libglapi-mesa but that is not InstVer, ignoring
  Conflicts//Breaks against version 10.3.2-0ubuntu1~trusty2 for libglapi-mesa-lts-utopic but that is not InstVer, ignoring
  Fixing libglapi-mesa-lts-vivid:i386 via keep of libglapi-mesa:amd64
Investigating (0) xserver-xorg-lts-vivid [ amd64 ] < 1:7.7+7ubuntu3~trusty1 > ( x11 )
Broken xserver-xorg-lts-vivid:amd64 Conflicts on libgles2-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) (>= 0~)
  Considering libgles2-mesa:amd64 0 as a solution to xserver-xorg-lts-vivid:amd64 0
  Removing xserver-xorg-lts-vivid:amd64 rather than change libgles2-mesa:amd64
Investigating (0) libgles2-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
Broken libgles2-mesa:amd64 Depends on libglapi-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) (= 10.1.3-0ubuntu0.5)
  Considering libglapi-mesa:amd64 -2 as a solution to libgles2-mesa:amd64 0
  Holding Back libgles2-mesa:amd64 rather than change libglapi-mesa:amd64
Investigating (0) gstreamer1.0-plugins-bad [ amd64 ] < 1.2.4-1~ubuntu1 > ( universe/libs )
Broken gstreamer1.0-plugins-bad:amd64 Depends on libgles2-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) (>= 7.8.1)
  Considering libgles2-mesa:amd64 0 as a solution to gstreamer1.0-plugins-bad:amd64 0
  Try Installing libgles2-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) before changing gstreamer1.0-plugins-bad:amd64
Investigating (0) libqt5gui5 [ i386 ] < none -> 5.2.1+dfsg-1ubuntu14.3 > ( libs )
Broken libqt5gui5:i386 Depends on libegl1-mesa [ i386 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) (>= 7.8.1)
  Considering libegl1-mesa:i386 -2 as a solution to libqt5gui5:i386 -1
  Holding Back libqt5gui5:i386 rather than change libegl1-mesa:i386
Broken libqt5gui5:i386 Depends on libegl1-x11 [ i386 ] < none > ( none )
  Considering libegl1-mesa-lts-vivid:i386 0 as a solution to libqt5gui5:i386 -1
  Holding Back libqt5gui5:i386 rather than change libegl1-x11:i386
  Or group keep for libqt5gui5:i386
Investigating (0) libgles2-mesa [ i386 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
Broken libgles2-mesa:i386 Depends on libglapi-mesa [ i386 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) (= 10.1.3-0ubuntu0.5)
  Considering libglapi-mesa:i386 -3 as a solution to libgles2-mesa:i386 -2
  Holding Back libgles2-mesa:i386 rather than change libglapi-mesa:i386
Investigating (1) libqt5widgets5 [ i386 ] < none -> 5.2.1+dfsg-1ubuntu14.3 > ( libs )
Broken libqt5widgets5:i386 Depends on libqt5gui5 [ i386 ] < none -> 5.2.1+dfsg-1ubuntu14.3 > ( libs ) (>= 5.2.0)
  Considering libqt5gui5:i386 -1 as a solution to libqt5widgets5:i386 9999
  Re-Instated libegl1-mesa:i386
  Re-Instated libglapi-mesa:i386
  Re-Instated libgles2-mesa:i386
  Re-Instated libqt5gui5:i386
Investigating (1) libglapi-mesa-lts-vivid [ amd64 ] < 10.5.9-2ubuntu1~trusty2 > ( libs )
Broken libglapi-mesa-lts-vivid:amd64 Conflicts on libglapi-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libglapi-mesa:amd64 -2 as a solution to libglapi-mesa-lts-vivid:amd64 5
  Added libglapi-mesa:amd64 to the remove list
  Conflicts//Breaks against version 10.1.0-4ubuntu5 for libglapi-mesa but that is not InstVer, ignoring
  Conflicts//Breaks against version 10.3.2-0ubuntu1~trusty2 for libglapi-mesa-lts-utopic but that is not InstVer, ignoring
Broken libglapi-mesa-lts-vivid:amd64 Conflicts on libglapi-mesa [ i386 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libglapi-mesa:i386 -3 as a solution to libglapi-mesa-lts-vivid:amd64 5
  Added libglapi-mesa:i386 to the remove list
  Conflicts//Breaks against version 10.1.0-4ubuntu5 for libglapi-mesa but that is not InstVer, ignoring
  Conflicts//Breaks against version 10.3.2-0ubuntu1~trusty2 for libglapi-mesa-lts-utopic but that is not InstVer, ignoring
  Fixing libglapi-mesa-lts-vivid:amd64 via keep of libglapi-mesa:amd64
  Fixing libglapi-mesa-lts-vivid:amd64 via keep of libglapi-mesa:i386
Investigating (1) libegl1-mesa-lts-vivid [ amd64 ] < 10.5.9-2ubuntu1~trusty2 > ( libs )
Broken libegl1-mesa-lts-vivid:amd64 Conflicts on libegl1-mesa [ i386 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libegl1-mesa:i386 -2 as a solution to libegl1-mesa-lts-vivid:amd64 2
  Added libegl1-mesa:i386 to the remove list
  Conflicts//Breaks against version 10.1.0-4ubuntu5 for libegl1-mesa but that is not InstVer, ignoring
  Conflicts//Breaks against version 10.3.2-0ubuntu1~trusty2 for libegl1-mesa-lts-utopic but that is not InstVer, ignoring
Broken libegl1-mesa-lts-vivid:amd64 Conflicts on libegl1-x11 [ i386 ] < none > ( none )
  Conflicts//Breaks against version 10.3.2-0ubuntu1~trusty2 for libegl1-mesa-lts-utopic but that is not InstVer, ignoring
  Considering libegl1-mesa:i386 -2 as a solution to libegl1-mesa-lts-vivid:amd64 2
  Added libegl1-mesa:i386 to the remove list
  Conflicts//Breaks against version 10.1.0-4ubuntu5 for libegl1-mesa but that is not InstVer, ignoring
  Fixing libegl1-mesa-lts-vivid:amd64 via keep of libegl1-mesa:i386
  Fixing libegl1-mesa-lts-vivid:amd64 via keep of libegl1-mesa:i386
Investigating (1) xorg [ amd64 ] < 1:7.7+1ubuntu8.1 > ( x11 )
Broken xorg:amd64 Depends on xserver-xorg [ amd64 ] < none -> 1:7.7+1ubuntu8.1 > ( x11 ) (>= 1:7.7+1ubuntu8.1)
  Considering xserver-xorg:amd64 1 as a solution to xorg:amd64 0
  Try Installing xserver-xorg [ amd64 ] < none -> 1:7.7+1ubuntu8.1 > ( x11 ) before changing xorg:amd64
Broken xorg:amd64 Depends on xserver-xorg-renamed [ amd64 ] < none > ( none )
  Considering xserver-xorg-lts-vivid:amd64 0 as a solution to xorg:amd64 0
  Or group remove for xorg:amd64
Broken xorg:amd64 Depends on libgl1-mesa-glx [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libgl1-mesa-glx:amd64 38 as a solution to xorg:amd64 0
  Try Installing libgl1-mesa-glx [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) before changing xorg:amd64
Broken xorg:amd64 Depends on libgl1-mesa-dri [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libgl1-mesa-dri:amd64 0 as a solution to xorg:amd64 0
  Removing xorg:amd64 rather than change libgl1-mesa-dri:amd64
Investigating (1) libgles1-mesa-dev [ amd64 ] < 10.1.3-0ubuntu0.5 > ( libdevel )
Broken libgles1-mesa-dev:amd64 Depends on libgles1-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) (= 10.1.3-0ubuntu0.5)
  Considering libgles1-mesa:amd64 -1 as a solution to libgles1-mesa-dev:amd64 0
  Try Installing libgles1-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) before changing libgles1-mesa-dev:amd64
Investigating (1) virtualbox-guest-x11 [ amd64 ] < 5.0.4-dfsg-2 > ( contrib/x11 )
Broken virtualbox-guest-x11:amd64 Depends on xorg-video-abi-19 [ amd64 ] < none > ( none )
  Considering xserver-xorg-core-lts-vivid:amd64 24 as a solution to virtualbox-guest-x11:amd64 0
  Removing virtualbox-guest-x11:amd64 rather than change xorg-video-abi-19:amd64
Investigating (1) gstreamer1.0-plugins-bad [ amd64 ] < 1.2.4-1~ubuntu1 > ( universe/libs )
Broken gstreamer1.0-plugins-bad:amd64 Depends on libegl1-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) (>= 7.8.1)
  Considering libegl1-mesa:amd64 1 as a solution to gstreamer1.0-plugins-bad:amd64 0
  Try Installing libegl1-mesa [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) before changing gstreamer1.0-plugins-bad:amd64
Investigating (1) libgbm1 [ amd64 ] < 10.1.3-0ubuntu0.5 > ( libs )
Broken libgbm1:amd64 Depends on libgl1-mesa-dri [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libgl1-mesa-dri:amd64 0 as a solution to libgbm1:amd64 0
  Removing libgbm1:amd64 rather than change libgl1-mesa-dri:amd64
Investigating (1) libglu1-mesa [ i386 ] < 9.0.0-2 > ( libs )
Broken libglu1-mesa:i386 Depends on libgl1-mesa-glx [ i386 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libgl1-mesa-glx:i386 3 as a solution to libglu1-mesa:i386 0
  Try Installing libgl1-mesa-glx [ i386 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) before changing libglu1-mesa:i386
Investigating (1) libgbm1 [ i386 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
Broken libgbm1:i386 Depends on libgl1-mesa-dri [ i386 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libgl1-mesa-dri:i386 0 as a solution to libgbm1:i386 -1
  Holding Back libgbm1:i386 rather than change libgl1-mesa-dri:i386
Investigating (1) libqt5gui5 [ i386 ] < none -> 5.2.1+dfsg-1ubuntu14.3 > ( libs )
Broken libqt5gui5:i386 Depends on libegl1-mesa [ i386 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) (>= 7.8.1)
  Considering libegl1-mesa:i386 -2 as a solution to libqt5gui5:i386 -1
  Holding Back libqt5gui5:i386 rather than change libegl1-mesa:i386
Broken libqt5gui5:i386 Depends on libegl1-x11 [ i386 ] < none > ( none )
  Considering libegl1-mesa-lts-vivid:i386 0 as a solution to libqt5gui5:i386 -1
  Holding Back libqt5gui5:i386 rather than change libegl1-x11:i386
  Or group keep for libqt5gui5:i386
Broken libqt5gui5:i386 Depends on libgbm1 [ i386 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) (>= 8.1~0)
  Considering libgbm1:i386 -1 as a solution to libqt5gui5:i386 -1
  Holding Back libqt5gui5:i386 rather than change libgbm1:i386
Investigating (2) libqt5widgets5 [ i386 ] < none -> 5.2.1+dfsg-1ubuntu14.3 > ( libs )
Broken libqt5widgets5:i386 Depends on libqt5gui5 [ i386 ] < none -> 5.2.1+dfsg-1ubuntu14.3 > ( libs ) (>= 5.2.0)
  Considering libqt5gui5:i386 -1 as a solution to libqt5widgets5:i386 9999
  Considering libqt5gui5:i386 -1 as a solution to libqt5widgets5:i386 9999
Broken libqt5widgets5:i386 Depends on libqt5gui5-gles [ i386 ] < none > ( none ) (>= 5.2.0)
Investigating (2) libcogl15 [ amd64 ] < 1.16.2-1 > ( libs )
Broken libcogl15:amd64 Depends on libegl1-mesa-drivers [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libegl1-mesa-drivers:amd64 1 as a solution to libcogl15:amd64 4
  Added libegl1-mesa-drivers:amd64 to the remove list
Broken libcogl15:amd64 Depends on libgbm1 [ amd64 ] < 10.1.3-0ubuntu0.5 > ( libs ) (>= 8.1~0)
  Considering libgbm1:amd64 0 as a solution to libcogl15:amd64 4
  Added libgbm1:amd64 to the remove list
  Fixing libcogl15:amd64 via keep of libegl1-mesa-drivers:amd64
  Fixing libcogl15:amd64 via keep of libgbm1:amd64
Investigating (2) libegl1-mesa-dev [ amd64 ] < 10.1.3-0ubuntu0.5 > ( libdevel )
Broken libegl1-mesa-dev:amd64 Depends on libegl1-mesa-drivers [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) (= 10.1.3-0ubuntu0.5)
  Considering libegl1-mesa-drivers:amd64 4 as a solution to libegl1-mesa-dev:amd64 2
  Try Installing libegl1-mesa-drivers [ amd64 ] < none -> 10.1.3-0ubuntu0.5 > ( libs ) before changing libegl1-mesa-dev:amd64
Investigating (2) ia32-libs [ amd64 ] < 2015.06.19 > ( admin )
Broken ia32-libs:amd64 Depends on libgl1-mesa-dri [ i386 ] < none -> 10.1.3-0ubuntu0.5 > ( libs )
  Considering libgl1-mesa-dri:i386 0 as a solution to ia32-libs:amd64 0
  Removing ia32-libs:amd64 rather than change libgl1-mesa-dri:i386
Investigating (3) libqt5widgets5 [ i386 ] < none -> 5.2.1+dfsg-1ubuntu14.3 > ( libs )
Broken libqt5widgets5:i386 Depends on libqt5gui5 [ i386 ] < none -> 5.2.1+dfsg-1ubuntu14.3 > ( libs ) (>= 5.2.0)
  Considering libqt5gui5:i386 -1 as a solution to libqt5widgets5:i386 9999
  Considering libqt5gui5:i386 -1 as a solution to libqt5widgets5:i386 9999
Broken libqt5widgets5:i386 Depends on libqt5gui5-gles [ i386 ] < none > ( none ) (>= 5.2.0)
Done
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:
 libqt5widgets5:i386 : Depends: libqt5gui5:i386 (>= 5.2.0) but it is not going to be installed or
                                libqt5gui5-gles:i386 (>= 5.2.0) but it is not installable
E: Unable to correct problems, you have held broken packages.

Maybe someone has experience interpreting what's happening here. Why is it bothering with so many amd64 libraries?