Auto merge of #12573 - eopb:12557-resolver-warning, r=weihanglo

Improve resolver version mismatch warning

fixes: #12557

Author: bors

src/cargo/core/workspace.rs

@@ -1021,11 +1021,18 @@ impl<'cfg> Workspace<'cfg> {
                         .max()
                     {
                         let resolver = edition.default_resolve_behavior().to_manifest();
-                        self.config.shell().warn(format_args!("some crates are on edition {edition} which defaults to `resolver = \"{resolver}\"`, but virtual workspaces default to `resolver = \"1\"`"))?;
+                        self.config.shell().warn(format_args!(
+                            "virtual workspace defaulting to `resolver = \"1\"` despite one or more workspace members being on edition {edition} which implies `resolver = \"{resolver}\"`"
+                        ))?;
                         self.config.shell().note(
                             "to keep the current resolver, specify `workspace.resolver = \"1\"` in the workspace root's manifest",
                         )?;
-                        self.config.shell().note(format_args!("to use the edition {edition} resolver, specify `workspace.resolver = \"{resolver}\"` in the workspace root's manifest"))?;
+                        self.config.shell().note(format_args!(
+                            "to use the edition {edition} resolver, specify `workspace.resolver = \"{resolver}\"` in the workspace root's manifest"
+                        ))?;
+                        self.config.shell().note(
+                            "for more details see https://doc.rust-lang.org/cargo/reference/resolver.html#resolver-versions",
+                        )?;
                     }
                 }
             }

tests/testsuite/features2.rs

@@ -1431,9 +1431,10 @@ fn edition_2021_workspace_member() {
     p.cargo("check")
         .with_stderr(
             "\
-warning: some crates are on edition 2021 which defaults to `resolver = \"2\"`, but virtual workspaces default to `resolver = \"1\"`
+warning: virtual workspace defaulting to `resolver = \"1\"` despite one or more workspace members being on edition 2021 which implies `resolver = \"2\"`
 note: to keep the current resolver, specify `workspace.resolver = \"1\"` in the workspace root's manifest
 note: to use the edition 2021 resolver, specify `workspace.resolver = \"2\"` in the workspace root's manifest
+note: for more details see https://doc.rust-lang.org/cargo/reference/resolver.html#resolver-versions
 [CHECKING] a v0.1.0 [..]
 [FINISHED] [..]
 ",