This makes building containers which can be used for cross development.
$ # ./debuild <docker-hub-account> <arch> <distro> <release>
$ ./debuild trapexit arm64 debian jessie
...
$ docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
trapexit/debian jessie-arm64 c1f28ad3c693 About a minute ago 355 MB
That image uses QEMU's user emulation to allow execution of non-native executables just as you would native one's. This particular image would provide an Debian Jessie image for ARM64. Convenient for doing cross compilation without needing the cross compilers installed locally.
On Debian / Ubuntu install qemu-user-static
in order to run the container.