[R] Should package be reinstalled when exterbal library is changed

[Marc Girondot]

Dear R-experts,

Some packages need external libraries to be installed. For example ncdf4 
needs netcdf library or flextable need pandoc.

When there is new version of external library, should the R package be 
installed again to use the new external version, or do the package finds 
itself the new version? Perhaps the answer is "It depends on the 
package", and so how to know if it requires new compilation or not ?

Thanks

Marc