The $(AR) command that is currently in Makevars.win does not work with llvm (needed on arm64 windows). However the fix is easy: these rules are actually redundant, because R's builtin Makefile already defines the proper rule for creating a static library from object files, here: https://github.com/r-devel/r-svn/blob/HEAD/src/gnuwin32/fixed/etc/Makeconf#L323-L326
So a simple solution is to simply remove this line. I confirmed that with this we can build stringi on arm64 on Windows.
This fixes https://github.com/gagolews/stringi/issues/497
The $(AR) command that is currently in Makevars.win does not work with llvm (needed on arm64 windows). However the fix is easy: these rules are actually redundant, because R's builtin Makefile already defines the proper rule for creating a static library from object files, here: https://github.com/r-devel/r-svn/blob/HEAD/src/gnuwin32/fixed/etc/Makeconf#L323-L326
So a simple solution is to simply remove this line. I confirmed that with this we can build stringi on arm64 on Windows.