R help - Aug 2023 - Problems with installing R packages from source and running C++ in R, even on fresh R installation

> This can be considered good news. You have just successfully performed
> the job that is normally done by R CMD SHLIB when installing source
> packages or running inline C++ code. The environment variables, at
> least inside your running R session, are completely fine.
>
> Now we need to find out why R CMD SHLIB itself fails without producing
> any output. Do you get any output from tools::Rcmd('SHLIB
--version')?
> Does tools::Rcmd('') print the list of available options?
Thanks again.
Here is the output before I changed anything in PATH:

```
> tools::Rcmd('SHLIB --version')
> tools::Rcmd('')
Usage: Rcmd command args

where 'command' is one of:
  INSTALL  Install add-on packages
  REMOVE   Remove add-on packages
  SHLIB    Make a DLL for use with dynload
  BATCH    Run R in batch mode
  build    Build add-on packages
  check    Check add-on packages
  Rprof    Post process R profiling files
  Rdconv   Convert Rd format to various other formats
  Rdiff    difference R output files
  Rd2pdf   Convert Rd format to PDF
  Rd2txt   Convert Rd format to pretty text
  Stangle   Extract S/R code from vignette
  Sweave    Process vignette documentation
  config   Obtain configuration information about R
  open     Open a file via Windows file associations
  texify   Process a latex file

Use
  Rcmd command --help
for usage information for each command.
```

So I get no output for tools::Rcmd('SHLIB --version').

I tried to run tools::Rcmd('SHLIB --help') or tools::Rcmd('check
--help'), but no output neither.

I had more success with tools::Rcmd('BATCH --help'):

```
> tools::Rcmd('BATCH --help')
Usage: Rcmd BATCH [options] infile [outfile]

Run R non-interactively with input from infile and place output (stdout
and stderr) to another file.  If not given, the name of the output file
is the one of the input file, with a possible '.R' extension stripped,
and '.Rout' appended.

Options:
  -h, --help            print short help message and exit
  -v, --version         print version info and exit
  --no-timing           do not report the timings
  --                    end processing of options

Further arguments starting with a '-' are considered as options as long
as '--' was not encountered, and are passed on to the R process, which
by default is started with '--restore --save'.

Report bugs at <https://bugs.R-project.org>.
```

I get exactly the same output after adding the paths to PATH in the System
variables part of the Environment variables box and before restarting my
computer. I had to change the / to \\ because my computer does not allow the
sign / for paths. So
C:\\rtools43/x86_64-w64-mingw32.static.posix/bin
became
C:\\rtools43\\x86_64-w64-mingw32.static.posix\\bin

After restart, I get the same output. I can also add that:

```
> tools::Rcmd('BATCH --version')
R batch front end: 4.3.1 (r84548)

Copyright (C) 1997-2023 The R Core Team.
This is free software; see the GNU General Public Licence version 2
or later for copying conditions.  There is NO warranty.
```

Best regards,
Christophe

? Thu, 31 Aug 2023 14:59:07 +0000
Christophe Bousquet <chr_bousquet at protonmail.com> ?????:
> So I get no output for tools::Rcmd('SHLIB --version').
> 
> I tried to run tools::Rcmd('SHLIB --help') or
tools::Rcmd('check
> --help'), but no output neither.
> 
> I had more success with tools::Rcmd('BATCH --help'):
The job of Rcmd.exe is to figure out where it's located and pass the
correct arguments to Rterm.exe (or some of the few other executables).

In a few cases (like `R CMD BATCH --help` or just `R CMD` without
arguments) it understands enough to produce the output by itself, which
you see. In most other cases (`SHLIB` or `check` with any arguments), it
constructs the command line to launch "${R_HOME}/bin/x64/Rterm.exe" -e
<something> and forwards the command line arguments there. For some
reason, the command line fails to produce any output.

Is there a "C:\Program Files\R\R-4.3.1\bin\x64\Rterm.exe"? If you
launch it, does it present an R command line?

I'm suspecting that Rcmd.exe somehow messes up when it tries to locate
Rterm.exe to launch it. Here's one way to see what happens:

1. Download Sysinternals Process Monitor, a free monitoring utility,
   from the Microsoft website and launch it (no installation needed):
   https://learn.microsoft.com/en-us/sysinternals/downloads/procmon

2. Set up the filter so that so that entries are included
 - Process name is "Rcmd.exe"
 - Operation is "Process Create"

3. Run tools::Rcmd('SHLIB --help') (or any other Rcmd invocation that
   fails to produce any output for you)

4. You should get one event of Rcmd.exe trying to launch cmd.exe with a
   long command line. What is the command line?

-- 
Best regards,
Ivan