Add comments to config.toml

.cargo/config.toml

@@ -5,5 +5,10 @@ r-test = "run --manifest-path ./savvy-cli/Cargo.toml -- test"
 # On Windows, link.exe fails when the artifact contains unresolved symbols
 # (i.e., R's API, which cannot be used without a real R session). This option
 # makes the linker ignore these problems.
+# 
+# This setting is needed only when you run `cargo test`, not when `R CMD check`
+# etc. The `.cargo` directory need to be excluded on building the package (i.e.
+# add `^src/rust/.cargo$` to `.Rbuildignore`) because otherwise you'll get the
+# "hidden files and directories" NOTE.
 [target.x86_64-pc-windows-msvc]
 rustflags = ["-C", "link-arg=/FORCE:UNRESOLVED"]

R-package/src/rust/.cargo/config.toml

@@ -1,5 +1,10 @@
 # On Windows, link.exe fails when the artifact contains unresolved symbols
 # (i.e., R's API, which cannot be used without a real R session). This option
 # makes the linker ignore these problems.
+# 
+# This setting is needed only when you run `cargo test`, not when `R CMD check`
+# etc. The `.cargo` directory need to be excluded on building the package (i.e.
+# add `^src/rust/.cargo$` to `.Rbuildignore`) because otherwise you'll get the
+# "hidden files and directories" NOTE.
 [target.x86_64-pc-windows-msvc]
 rustflags = ["-C", "link-arg=/FORCE:UNRESOLVED"]

savvy-bindgen/src/gen/templates/config_toml

@@ -1,5 +1,10 @@
 # On Windows, link.exe fails when the artifact contains unresolved symbols
 # (i.e., R's API, which cannot be used without a real R session). This option
 # makes the linker ignore these problems.
+# 
+# This setting is needed only when you run `cargo test`, not when `R CMD check`
+# etc. The `.cargo` directory need to be excluded on building the package (i.e.
+# add `^src/rust/.cargo$` to `.Rbuildignore`) because otherwise you'll get the
+# "hidden files and directories" NOTE.
 [target.x86_64-pc-windows-msvc]
 rustflags = ["-C", "link-arg=/FORCE:UNRESOLVED"]