[R] Error in readRDS(dest) (was Re: Error with installed.packages with R 3.4.0 on Windows)

[Patrick Connolly]

On Tue, 23-May-2017 at 12:20PM +0200, Martin Maechler wrote:

[...]

|> 
|> Given the above stack trace. 
|> It may be easier to just do
|> 
|>     debugonce(available.packages)
|>     install.packages("withr")
|> 
|> and then inside available.packages, (using 'n') step to the
|> point _before_ the tryCatch(...) call happens; there, e.g. use
|> 
|>       ls.str()
|> 
|> which gives an str() of all your local objects, notably 'dest'
|> and 'method'.
|> but you can also try other things once inside
|> available.packages().

I couldn't see any differences between R-3.3.3 (which works) and
R-3.4.0 (which doesn't) until I got to here, a few lines before the
download.file line:

Browse[2]> 
debug: dest <- file.path(tempdir(), paste0("repos_", URLencode(repos, 
    TRUE), ".rds"))
Browse[2]> 

When I check out those directories in a terminal, there's a big diffrence:

With R-3.4.0
~ > ll /tmp/RtmpFUhtpY
total 4
drwxr-xr-x 2 hrapgc hrapgc 4096 May 31 10:45 downloaded_packages/
-rw-r--r-- 1 hrapgc hrapgc    0 May 31 10:56 repos_http%3A%2F%2Fcran.stat.auckland.ac.nz%2Fsrc%2Fcontrib.rds


With R-3.3.3
~ > ll /tmp/RtmpkPgL3A
total 380
drwxr-xr-x 2 hrapgc hrapgc   4096 May 31 11:01 downloaded_packages/
-rw-r--r-- 1 hrapgc hrapgc   8214 May 31 11:01 libloc_185_3165c7f52d5fdf96.rds
-rw-r--r-- 1 hrapgc hrapgc 372263 May 31 11:01 repos_http%3A%2F%2Fcran.stat.auckland.ac.nz%2Fsrc%2Fcontrib.rds

So, if I could figure out what makes *that* difference I could get
somewhere.  I see there's considerably extra code in the newer of the
two versions of available.packages() but being a bear with a small
brain, I can't figure out what differences should be expected.  I have
no idea what populates those 'dest' directories.

TIA
-- 
~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.   
   ___    Patrick Connolly   
 {~._.~}                   Great minds discuss ideas    
 _( Y )_  	         Average minds discuss events 
(:_~*~_:)                  Small minds discuss people  
 (_)-(_)  	                      ..... Eleanor Roosevelt
	  
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