Issue with install_libR_bindings

[CGMossa]

I've tried to use rextendr at another machine, and received this error:

> library(rextendr)
> install_libR_bindings(force = TRUE, quiet = FALSE)
build directory: C:\Users\tpb398\AppData\Local\Temp\Rtmp8uYQNw\file527c2f3c6a03
error: no such subcommand: `LIBRSYS_BINDINGS_DIR=C:/Users/tpb398/Documents/R/win-library/3.6/rextendr/rust/libR-sys/src`

[clauswilke]

But it works on your other Windows machine?

The problem is here: https://github.com/clauswilke/rextendr/blob/85a2c458fbb3c8150013bb735c6a74b7eaf77586/R/install_libR_bindings.R#L54-L68 The system2() call needs to set an environment variable, using the env argument. I would have hoped it did that correctly, but apparently it doesn't.

[clauswilke]

So env doesn't seem to work on Windows:

On Windows, env is only supported for commands such as R and make which accept environment variables on their command line.

Therefore, we'll have to find some other way to hand this info through to build.rs. Does cargo accept environment variables as command-line argument?

[clauswilke]

@CGMossa Does the solution described here: https://stackoverflow.com/a/39908765/4975218 work for you?

[CGMossa]

This however works:

  Sys.setenv(
      LIBRSYS_BINDINGS_DIR = file.path(package_dir, "rust", "libR-sys", "src"))

  system2(
    command = "cargo",
    args = c(
      "build",
      sprintf("--manifest-path=%s", file.path(dir, "Cargo.toml"))
    ),
    stdout = stdout,
    stderr = stdout
  )

[CGMossa]

@CGMossa Does the solution described here: https://stackoverflow.com/a/39908765/4975218 work for you?

I don't know what to tell you, but that doesn't work at all. I just don't get what I'm not seeing. The thing I did above works.

Also, am I supposed to write this:

install_libR_bindings(force = TRUE, quiet = FALSE, patch.crates_io = "libR-sys = {path = \"C:/Users/tpb398/Documents/github/libR-sys\"}")

?

[clauswilke]

Ok, I just committed the fix you proposed. The patch.crates_io argument will go away once we update libR-sys on crates.io.