I’ve been able to successfully launch Cura LE on Ubuntu 18.04 by doing a local build to get around the dependency issue. Here’s the instructions to do so if you wish to try it yourself:
Install build libraries and dependencies
sudo apt-get install python libsm-dev libxi-dev libfontconfig1-dev libbsd-dev libxdmcp-dev libxcb1-dev libgl1-mesa-dev libgcrypt20-dev liblz4-dev liblzma-dev libselinux1-dev libsystemd-dev libdbus-1-dev libstdc++-6-dev libglib2.0-dev libc6-dev libssl1.0-dev libtinfo-dev libreadline-dev libharfbuzz-dev libxkbcommon-dev gfortran gcc uuid-dev git wget curl cmake build-essential
Setup project directories
mkdir Projects && mkdir Projects/cura
cd into our cura directory
cd Projects/cura/
Clone into repo
git clone https://code.alephobjects.com/source/curabuild-lulzbot.git build-master
Create folders for build
mkdir build-master/build && cd build-master
Run the build script. Go ahead and put that casserole in the oven - this could take about 90 minutes.
./build_deb_package.sh
Install the freshly-generated DEB package. Replace 3.6.15 with your version if different.
cd && sudo dpkg -i Projects/cura/build-master/build/cura-lulzbot-3.6.15-Linux.deb