library load time is very long

The library function call is very slow. Here are some benchmarks:

Rscript -e "microbenchmark::microbenchmark(library(devtools), times=1, unit='seconds')"
Unit: seconds
              expr       min        lq      mean    median        uq       max
 library(devtools) 0.7143343 0.7143343 0.7143343 0.7143343 0.7143343 0.7143343
 neval
     1

Rscript -e "microbenchmark::microbenchmark(library(dplyr), times=1, unit='seconds')"
Unit: seconds
           expr       min        lq      mean    median        uq       max
 library(dplyr) 0.3258483 0.3258483 0.3258483 0.3258483 0.3258483 0.3258483
 neval
     1


databio/lab|~$ Rscript -e "microbenchmark::microbenchmark(library(bedbaser), times=1, unit='seconds')"
Unit: seconds
              expr      min       lq     mean   median       uq      max neval
 library(bedbaser) 8.686374 8.686374 8.686374 8.686374 8.686374 8.686374     1


databio/lab|~$ Rscript -e "microbenchmark::microbenchmark(library(LOLA), times=1, unit='seconds')"
Unit: seconds
          expr      min       lq     mean   median       uq      max neval
 library(LOLA) 2.352586 2.352586 2.352586 2.352586 2.352586 2.352586     1

devtools: 0.71 seconds
dplyr: 0.33 seconds
bedbaser: 8.7 seconds
LOLA: 2.4 seconds

For a package that is just a simple API interface, does this seem longer than should be necessary to load a package?

Start by reproducing the reported Rscript microbenchmark for library(bedbaser) and compare it with the listed devtools, dplyr, and LOLA timings. Profile package startup to identify what accounts for the load time; done means the startup cost is reduced and the benchmark is rerun to document the result.