This downloads all references in a bibtex file as pdf if shorthands are used. If it doesn't make sense to download a file as pdf (e.g. png) it will try to save it in the native format.
Run make build. There's also an automated build at docker hub at ps1337/bibtex2pdf-docker
Use make run as non-root user and make sure the data folder can be accessed by your user. Be sure to provide the required file(s).
Because some kernels still don't allow user namespaces.