write a library under 2.0.1 version

On Tue, 1 Mar 2005 marta at statistica.it wrote:

I had written a library under R 1.9.0 and now I would like to import that
library under R 2.0.1
Apparently it does not work; I can install the package, but when I try to
read it the error is the following:

Error in library(compvar) : 'compvar' is not a valid package -- installed
< 2.0.0

[SNIP]

You install the package with R CMD INSTALL, just as was documented for
1.9.1.  See the `Writing R Extensions' and `R Installation and
Administration' manuals.

Out of curiousity, just how often has the package installation
compatibility between versions been an issue? Would it perhaps
be beneficial to version personal directories by major version?
I.e. instead of having just "~/R/library", would it be better
to have "~/R/1.x/library" and "~/R/2.x/library" and have the
.Rprofile select appropriately depending on version of R being
executed? If so, maybe this question would cease to be an issue.

I'd be interested to know how Prof. Ripley's R_LIBS variable
is defined, if he wouldn't mind sharing. Also curious if most
people keep BioConductor packages installed separately in a
third location.

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