[R-SIG-Mac] how to install RODBC on macOS Sierra 10.12.4?

[Spencer Graves]

Hello:


       I recently upgraded to R 3.4.0, and I've so far been unable to 
"install.packages('RODBC')" or "R CMD INSTALL RODBC_1.3-15.tar.gz". Both 
end with the following:


configure: error: "ODBC headers sql.h and sqlext.h not found"
ERROR: configuration failed for package ‘RODBC’


       I had RODBC installed in R 3.3, but that was before I upgraded to 
macOS Sierra 10.12.4.   I've tried to RTFM, but I don't know which FMTR, 
and I can't decrypt the documentation I've found that seem relevant.  I 
couldn't find the answer in Ripley's "ODBC Connectivity" vignette.


       "iodbc-42.5/iodbc/README.MACOSX" says, "You first need to install 
the latest Mac OS X Developer Packages, which can be found at 
"http://developer.apple.com/tools".  I think I've done that, but I don't 
know how to check it.


       "iodbc-42.5/iodbc/README.MACOSX" continues, "Then, you can open 
the Xcode Project Builder files under mac/iODBCinst, mac/iODBC, 
mac/iODBCtest and mac/iODBCtestw,".  I don't know how find any of 
these.  It further continues, "or execute the following commands from a 
terminal session to build all the frameworks and demo applications:


     $ cd mac
     $ make"


       I just did "$ cd mac" and got, "-bash: cd: mac: No such file or 
directory".  Evidently, I need to substitute something for "mac" here, 
but I don't know what.



       Suggestions?  Thanks,
       Spencer Graves