[Rd] codetools really optional for R CMD check?

[Ross Boylan]

After upgrading to R 2.5.1 on Debian, R CMD check gives
* checking Rd cross-references ... WARNING
Error in .find.package(package, lib.loc) : 
	there is no package called 'codetools'
Execution halted
* checking for missing documentation entries ... WARNING
etc

The NEWS file says (for 2.5.0; I was on 2.4 before the recent upgrade)
    o	New recommended package 'codetools' by Luke Tierney provides
	code-analysis tools.  This can optionally be used by 'R CMD
	check' to detect problems, especially symbols which are not
	visible.

This sounds as if R CMD check should run OK without the package, and it
doesn't seem to.

Have I misunderstood something, or is their a problem with R CMD check's
handling of the case with missing codetools.

I don't have codetools installed because the Debian r-recommended
package was missing a dependency; I see that's already been fixed
(wow!).

Ross