Install should fail if there's an error copying DLL on Windows

[wch]

If a package is currently loaded on Windows and you try to install over it, some of the files will be copied over, but the DLL will not.

Real-world example here: r-lib/scales#101

To reproduce:

> library(scales)
> remotes::install_github("hadley/scales")
Downloading GitHub repo hadley/scales@master
Installing package into ‘C:/Users/IEUser/Documents/R/win-library/3.4’
(as ‘lib’ is unspecified)
* installing *source* package 'scales' ...
** libs

*** arch - i386
c:/Rtools/mingw_32/bin/g++  -I"C:/PROGRA~1/R/R-34~1.0/include" -DNDEBUG  -I"C:/Users/IEUser/Documents/R/win-library/3.4/Rcpp/include"   -I"d:/Compiler/gcc-4.9.3/local330/include"     -O2 -Wall  -mtune=core2 -c RcppExports.cpp -o RcppExports.o
c:/Rtools/mingw_32/bin/g++  -I"C:/PROGRA~1/R/R-34~1.0/include" -DNDEBUG  -I"C:/Users/IEUser/Documents/R/win-library/3.4/Rcpp/include"   -I"d:/Compiler/gcc-4.9.3/local330/include"     -O2 -Wall  -mtune=core2 -c colors.cpp -o colors.o
c:/Rtools/mingw_32/bin/g++ -shared -s -static-libgcc -o scales.dll tmp.def RcppExports.o colors.o -Ld:/Compiler/gcc-4.9.3/local330/lib/i386 -Ld:/Compiler/gcc-4.9.3/local330/lib -LC:/PROGRA~1/R/R-34~1.0/bin/i386 -lR
installing to C:/Users/IEUser/Documents/R/win-library/3.4/scales/libs/i386

*** arch - x64
c:/Rtools/mingw_64/bin/g++  -I"C:/PROGRA~1/R/R-34~1.0/include" -DNDEBUG  -I"C:/Users/IEUser/Documents/R/win-library/3.4/Rcpp/include"   -I"d:/Compiler/gcc-4.9.3/local330/include"     -O2 -Wall  -mtune=core2 -c RcppExports.cpp -o RcppExports.o
c:/Rtools/mingw_64/bin/g++  -I"C:/PROGRA~1/R/R-34~1.0/include" -DNDEBUG  -I"C:/Users/IEUser/Documents/R/win-library/3.4/Rcpp/include"   -I"d:/Compiler/gcc-4.9.3/local330/include"     -O2 -Wall  -mtune=core2 -c colors.cpp -o colors.o
c:/Rtools/mingw_64/bin/g++ -shared -s -static-libgcc -o scales.dll tmp.def RcppExports.o colors.o -Ld:/Compiler/gcc-4.9.3/local330/lib/x64 -Ld:/Compiler/gcc-4.9.3/local330/lib -LC:/PROGRA~1/R/R-34~1.0/bin/x64 -lR
installing to C:/Users/IEUser/Documents/R/win-library/3.4/scales/libs/x64
Warning in file.copy(files, dest, overwrite = TRUE) :
  problem copying .\scales.dll to C:\Users\IEUser\Documents\R\win-library\3.4\scales\libs\x64\scales.dll: Permission denied
** R
** preparing package for lazy loading
** help
Loading required package: scales
*** installing help indices
** building package indices
** testing if installed package can be loaded
*** arch - i386
*** arch - x64
* DONE (scales)

[gaborcsardi]

I think this is coming from install.packages, so it is a bug in base R. It should fail instead of the warning.

[wch]

When I try to use install.packages, it just doesn't allow it (R 3.4.0, Windows):

> install.packages('scales')
Installing package into ‘C:/Users/IEUser/Documents/R/win-library/3.4’
(as ‘lib’ is unspecified)
trying URL 'https://cloud.r-project.org/bin/windows/contrib/3.4/scales_0.5.0.zip'
Content type 'application/zip' length 695672 bytes (679 KB)
downloaded 679 KB

package ‘scales’ successfully unpacked and MD5 sums checked
Warning: cannot remove prior installation of package ‘scales’

The downloaded binary packages are in
        C:\Users\IEUser\AppData\Local\Temp\Rtmp6PvtwD\downloaded_packages

And when I try to install it using R CMD INSTALL (while scales is loaded in an R session), it says:

C:\Users\IEUser\Downloads>R CMD INSTALL scales_0.5.0.zip
* installing to library 'C:/Users/IEUser/Documents/R/win-library/3.4'
package 'scales' successfully unpacked and MD5 sums checked
Warning: cannot remove prior installation of package 'scales'

[gaborcsardi]

Looks like the behavior is different for source and binary packages then. Still, this is coming from install.packages.

[wch]

Oops, you're right - when I use type="source", it installs the files except for the DLL.

[gaborcsardi]

We'll handle this better in pkginstall.

[jimhester]

I looked into this again and unfortunately R CMD INSTALL unconditionally sets options(warn = 1), so it is not possible to override this in a temporary .RProfile to change the behavior. I opened an issue suggesting this line be removed https://bugs.r-project.org/bugzilla/show_bug.cgi?id=17453.

We could do something like

library(glue)
system2("Rterm.exe", c(
  "-e",
  shQuote("withCallingHandlers(tools:::.install_packages(commandArgs(TRUE)), warning = function(e) stop(e))"),
  "--args",
  "glue_1.3.0.tar.gz"
  )
)

Which does convert the warnings to errors, but it seems somewhat fragile.

Other approaches; such as checking the packages for integrity by md5 hashing seem out of scope for remotes right now.

[gaborcsardi]

Other approaches; such as checking the packages for integrity by md5 hashing seem out of scope for remotes right now.

AFAIR, on Windows, where this matters, R hashes all files, so we would only need to check the hashes.

[jimhester]

So Martin Maechler changed tools:::.install_packges() (which is what R CMD INSTALL calls) in R-devel so that it respects options(warn = 2) wch/r-source@828a04f, so we could now do this on later versions of R.