* installing *source* package ‘dtmapi’ ...
** using staged installation
** R
** byte-compile and prepare package for lazy loading
Error in library(httr) : there is no package called ‘httr’
Error: unable to load R code in package ‘dtmapi’
Execution halted
ERROR: lazy loading failed for package ‘dtmapi’
* removing ‘/srv/hornik/tmp/CRAN_pretest/dtmapi.Rcheck/dtmapi’