To cite package ‘defer’ in publications use:

FitzJohn R (2019). defer: Defer Errors. R package version 0.1.0, https://github.com/mrc-ide/odin.

Corresponding BibTeX entry:

  @Manual{,
    title = {defer: Defer Errors},
    author = {Rich FitzJohn},
    year = {2019},
    note = {R package version 0.1.0},
    url = {https://github.com/mrc-ide/odin},
  }