When package code is executed and the implications

[jennybc]

Capturing enough from a recent Slack conversation that we don't forget this ...

Have a nice table with R CMD build, R CMD INSTALL, library(pkg) and pkg::fun() and then showing what code is executed for each

Context: appreciating build-time dependencies (r-lib/devtools#1788) or, more generally, build-time definitions (could also be data, such as crayon's regrettable caching of color capabilities at build time).

cc @gaborcsardi

[jennybc]

Example: you want to express "let my foo be their foo". These are more different than you might think:

foo <- pkgB::foo

vs

foo <- function(...) pkgB::foo(...)