Fix cfg information in Rust docs

- support building Rust docs for docs.rs in `Makefile`

Author: tyranron

.github/workflows/ci.yml

@@ -167,9 +167,9 @@ jobs:
       - uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: stable
+          toolchain: nightly
 
-      - run: make cargo.doc private=yes open=no
+      - run: make cargo.doc private=yes docsrs=yes open=no
 
 
 

Makefile

@@ -40,14 +40,16 @@ test: test.cargo
 # Generate crate documentation from Rust sources.
 #
 # Usage:
-#	make cargo.doc [private=(yes|no)]
+#	make cargo.doc [private=(yes|no)] [docsrs=(no|yes)]
 #	               [open=(yes|no)] [clean=(no|yes)]
 
 cargo.doc:
 ifeq ($(clean),yes)
 	@rm -rf target/doc/
 endif
-	cargo doc -p cucumber-expressions --all-features \
+	$(if $(call eq,$(docsrs),yes),RUSTDOCFLAGS='--cfg docsrs',) \
+	cargo $(if $(call eq,$(docsrs),yes),+nightly,) doc -p cucumber-expressions \
+		--all-features \
 		$(if $(call eq,$(private),no),,--document-private-items) \
 		$(if $(call eq,$(open),no),,--open)
 

src/lib.rs

@@ -111,7 +111,7 @@
     unused_results,
     variant_size_differences
 )]
-#![cfg_attr(docsrs, feature(doc_cfg))]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
 
 pub mod ast;
 mod combinator;