[ESS-bugs] ESS 13.09-1 with old R versions fails pretty badly

[Martin Maechler]

As an R core developer,
I have many old versions of R installed, that I occasionally use
for testing, comparison etc.

I just found that this is quite a problem with the new ESSR (or
other?) behavior of ESS.
Of course ESSR is nowadays installed for me (in a private library),
but the installation from R 3.0.2 cannot be used in R 2.1.1  (e.g.) :

> require("ESSR")
Loading required package: ESSR
Error in eval(expr, envir, enclos) : couldn't find function ".getNamespace"
In addition: Warning message:
package 'ESSR' was built under R version 3.0.2 
Error: unable to load R code in package 'ESSR'
[1] FALSE
> 

For that reason, ESS trys to call install.packages(...)
but fails with that as well ...

One reason that you now name the package tarball  ESSR.tar.gz
instead of  ESSR_<ver>.tar.gz

The latter is required for old(er) versions of R.

But even then, problems don't end.
The R code can't even be *parse*d because it uses '0L' which did
not exist in R 2.1.1 (e.g.).... actually I want to use even
older versions of R.

Of course, we can argue that "nobody uses such old versions of R",
but as you see it's not quite true,
and the problem really that ``almost nothing works'' now when
ESSR is not available, not even simple  function name TAB
completion, or even '?' fails because .ess_help is undefined.

I think we need a workaround for old R versions such that a bit
more things work than now...

Martin