HowTo Run AppImage on unsupported systems

If you get messages like shown bellow, then it seems you are running on a system that is too old.

The build system for AppImage binary is currently Ubuntu 16.04 - this then should run on all distributions which are ~same date or more recent then selected build system (e.g. Ubuntu 16.04). So basically, if build with 16.04, then all newer distribution then 2016 should be OK. At least in theory :)

There is docker setup for build on Ubuntu 14.04 - see "development/docker/Dockerfile.ubuntu_xenial". But it doesn't work yet. Pull request welcome

Example:

ubuntu@ubuntu:~/Downloads$ chmod a+x NixNote.AppImage
ubuntu@ubuntu:~/Downloads$ ./NixNote.AppImage
./NixNote.AppImage: /usr/lib/x86_64-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.21' not found (required by ./NixNote.AppImage)
./NixNote.AppImage: /usr/lib/x86_64-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.21' not found (required by /tmp/.mount_NixNotlqf11u/usr/bin/../lib/libQt5WebKit.so.5)
./NixNote.AppImage: /usr/lib/x86_64-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.20' not found (required by /tmp/.mount_NixNotlqf11u/usr/bin/../lib/libQt5WebKit.so.5)

Another example (with extracted AppImage):

ubuntu@ubuntu:~/Downloads/squashfs-root$ ./AppRun
./AppRun: /usr/lib/x86_64-linux-gnu/libstdc++.so.6: version GLIBCXX_3.4.21' not found (required by ./AppRun)
./AppRun: /usr/lib/x86_64-linux-gnu/libstdc++.so.6: version GLIBCXX_3.4.21' not found (required by /home/ubuntu/Downloads/squashfs-root/usr/bin/../lib/libQt5WebKit.so.5)
./AppRun: /usr/lib/x86_64-linux-gnu/libstdc++.so.6: version GLIBCXX_3.4.20' not found (required by /home/ubuntu/Downloads/squashfs-root/usr/bin/../lib/libQt5WebKit.so.5)

...