[R] RODBC installation: error message

[gregory benison]

If one attempts to install RODBC (via install.packages('RODBC'))
without having an ODBC driver installed, this error message results:

checking sqlext.h presence... no
checking for sqlext.h... no
configure: error: "ODBC headers sql.h and sqlext.h not found"
ERROR: configuration failed for package 'RODBC'
* removing '/usr/lib/R/library/RODBC'

Yes, the RODBC README describes the needed prerequisites, but for
someone who just wants to use RODBC and tries to install it in the
most natural way, i.e. from "R Installation and Administration":

> For most users it suffices to call ‘install.packages(pkgname)’

the result is the above error message, which could be more informative.

Greg Benison