Jim Hester

I don't think it is really feasible to do generally in remotes, but you can avoid it by using `install_dev()` rather than `install_github()` assuming you have the CRAN package installed....

I think one way you could support 3 or 4 simultaneous progress bars on one line is using [unicode braille patterns](https://en.wikipedia.org/wiki/Braille_Patterns#Chart) ``` [⠿⠿⠟⠛⠛⠛⠒⠒⠒⠒ ] ```

This would be easy to do if all R terminals supported the [ANSI escape sequence to move the cursor up lines](http://ascii-table.com/ansi-escape-sequences.php) unfortunately some (notably the default windows terminal) does not,...

Most of what `--as-cran` does is here https://github.com/wch/r-source/blob/722824a89bcc9bcd6848abcb80ce4f7f21246e1b/src/library/tools/R/check.R#L6430-L6503, though there are a a few other places that explicitly check for the `as_cran` variable. I agree there is no perfect solution,...

Yes, it definitely will, the CXX17 macro won't be set with the current Windows toolchain for instance.

Well actually this change doesn't actually affect Windows, since this only changes Makevars and not Makevars.win, but the underlying issue is the same, if R wasn't built with a compiler...

Some notes after looking into this. implementing `copy_address()` seems quite straightforward, another straightforward implementation is in https://github.com/googleprojectzero/TinyInst/blob/3f39189be930e805d16c98555d3e3fc0a4b1d403/macOS/machtarget.cpp#L170-L219. I have a simple implementation locally that seems to work. Locating the `libR.dylib`...

https://github.com/llvm/llvm-project/tree/main/libunwind is also probably useful for stack unwinding on macOS. It is what lldb uses.

I think roxygen needs access the objects in general, but perhaps for this use case we might be able to avoid it? I don't think the current API has any...

Do you have an example package where you are seeing this? Pretty sure the code already does the things you mention.