Propagate the error causing rextendr::document() to fail

[CGMossa]

This has been a nuisance for many, many years now already.

Invoking rextendr::document() invokes {callr}'s r function, which spawns a separate R process, meant to load the wrapper-generating functions that are part of the rust-powered r-package, and write that to disk. Unfortunately, if there are any errors attributed with this call, then we do not see the error. The error could be missing libraries in Makevars (there are related issues), or anything similar, then you don't get the error message.

With this slight change, the error message is propagated.

Example

Current behaviour:

Error in `value[[3L]]()`:
! Failed to generate wrapper functions.
✖ in callr subprocess.
Backtrace:
    ▆
 1. └─rextendr::document()
 2.   └─rextendr::register_extendr(path = pkg, quiet = quiet)
 3.     └─base::tryCatch(...)
 4.       └─base (local) tryCatchList(expr, classes, parentenv, handlers)
 5.         └─base (local) tryCatchOne(expr, names, parentenv, handlers[[1L]])
 6.           └─value[[3L]](cond)
 7.             └─cli::cli_abort(...)
 8.               └─rlang::abort(...)

New behaviour:

Error in `value[[3L]]()`:
! Failed to generate wrapper functions.
✖ in callr subprocess.
"wrap2__make_extendrtests_wrappers" not available for .Call() for package "extendrtests"

And yes I was refactoring the way wrapper-generating works in extendr-macros+extendr-api.

[Ilia-Kosenkov]

@CGMossa , could you please run {lintr} over your changes?

[CGMossa]

I thought I did that. But maybe I didn't. I tried again now.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.

Project coverage is 82.95%. Comparing base (4217a0e) to head (69f6b10).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
R/register_extendr.R	0.00%	4 Missing ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
R/register_extendr.R	72.54% <0.00%> (-2.20%)	⬇️