Setting a custom CRAN mirror

[mattinbits]

Setting a custom CRAN mirror, for example using .Rprofile, doesn't appear to have an impact on needs as it does when calling install.packages directly. It appears to be hard coded to the Rstudio CRAN mirror in needs.R:

utils::install.packages(missing, repos = "http://cran.rstudio.com/",
                                quiet = T)

Is there a method to set a custom CRAN mirror when installing using the needs package?