docs.rs: use unique cfg for enabling nightly doc options

Author: ctz

.github/workflows/ci.yml

@@ -55,15 +55,15 @@ jobs:
             - name: cargo doc (ring)
               run: cargo doc --features ring,pem,x509-parser --document-private-items
               env:
-                  RUSTDOCFLAGS: ${{ matrix.toolchain == 'nightly' && '-Dwarnings --cfg=docsrs' || '-Dwarnings' }}
+                  RUSTDOCFLAGS: ${{ matrix.toolchain == 'nightly' && '-Dwarnings --cfg=rcgen_docsrs' || '-Dwarnings' }}
             - name: cargo doc (aws_lc_rs_unstable)
               run: cargo doc --features aws_lc_rs_unstable,pem,x509-parser --document-private-items
               env:
-                  RUSTDOCFLAGS: ${{ matrix.toolchain == 'nightly' && '-Dwarnings --cfg=docsrs' || '-Dwarnings' }}
+                  RUSTDOCFLAGS: ${{ matrix.toolchain == 'nightly' && '-Dwarnings --cfg=rcgen_docsrs' || '-Dwarnings' }}
             - name: cargo doc (fips)
               run: cargo doc --no-default-features --features fips --document-private-items
               env:
-                  RUSTDOCFLAGS: ${{ matrix.toolchain == 'nightly' && '-Dwarnings --cfg=docsrs' || '-Dwarnings' }}
+                  RUSTDOCFLAGS: ${{ matrix.toolchain == 'nightly' && '-Dwarnings --cfg=rcgen_docsrs' || '-Dwarnings' }}
 
     check-external-types:
         name: Validate external types appearing in public API

rcgen/Cargo.toml

@@ -45,10 +45,14 @@ required-features = ["crypto", "pem"]
 
 [package.metadata.docs.rs]
 features = ["aws_lc_rs",  "aws_lc_rs_unstable", "crypto", "ring", "x509-parser"]
+rustdoc-args = ["--cfg", "rcgen_docsrs"]
 
 [package.metadata.cargo_check_external_types]
 allowed_external_types = [
     "time::offset_date_time::OffsetDateTime",
     "zeroize::Zeroize",
     "rustls_pki_types::*",
 ]
+
+[lints.rust]
+unexpected_cfgs = { level = "warn", check-cfg = ["cfg(rcgen_docsrs)"] }

rcgen/src/lib.rs

@@ -29,7 +29,7 @@ println!("{}", signing_key.serialize_pem());
 #![forbid(unsafe_code)]
 #![forbid(non_ascii_idents)]
 #![deny(missing_docs)]
-#![cfg_attr(docsrs, feature(doc_cfg, doc_auto_cfg))]
+#![cfg_attr(rcgen_docsrs, feature(doc_cfg, doc_auto_cfg))]
 #![warn(unreachable_pub)]
 
 use std::borrow::Cow;