feat: Stabilize MSRV-aware resolver config

This includes
- `cargo generate-lockfile --ignore-rust-version`
- `cargo update --ignore-rust-version`

This does not include
- `edition = "2024"`
- `resolver = "3"`

Author: epage

src/bin/cargo/commands/generate_lockfile.rs

@@ -8,23 +8,13 @@ pub fn cli() -> Command {
         .arg_silent_suggestion()
         .arg_manifest_path()
         .arg_lockfile_path()
-        .arg_ignore_rust_version_with_help(
-            "Ignore `rust-version` specification in packages (unstable)",
-        )
+        .arg_ignore_rust_version_with_help("Ignore `rust-version` specification in packages")
         .after_help(color_print::cstr!(
             "Run `<cyan,bold>cargo help generate-lockfile</>` for more detailed information.\n"
         ))
 }
 
 pub fn exec(gctx: &mut GlobalContext, args: &ArgMatches) -> CliResult {
-    if args.honor_rust_version().is_some() {
-        gctx.cli_unstable().fail_if_stable_opt_custom_z(
-            "--ignore-rust-version",
-            9930,
-            "msrv-policy",
-            gctx.cli_unstable().msrv_policy,
-        )?;
-    }
     let ws = args.workspace(gctx)?;
     ops::generate_lockfile(&ws)?;
     Ok(())

src/bin/cargo/commands/update.rs

@@ -53,24 +53,13 @@ pub fn cli() -> Command {
         )
         .arg_manifest_path()
         .arg_lockfile_path()
-        .arg_ignore_rust_version_with_help(
-            "Ignore `rust-version` specification in packages (unstable)",
-        )
+        .arg_ignore_rust_version_with_help("Ignore `rust-version` specification in packages")
         .after_help(color_print::cstr!(
             "Run `<cyan,bold>cargo help update</>` for more detailed information.\n"
         ))
 }
 
 pub fn exec(gctx: &mut GlobalContext, args: &ArgMatches) -> CliResult {
-    if args.honor_rust_version().is_some() {
-        gctx.cli_unstable().fail_if_stable_opt_custom_z(
-            "--ignore-rust-version",
-            9930,
-            "msrv-policy",
-            gctx.cli_unstable().msrv_policy,
-        )?;
-    }
-
     let mut ws = args.workspace(gctx)?;
 
     if args.is_present_with_zero_values("package") {

src/cargo/core/workspace.rs

@@ -306,31 +306,12 @@ impl<'gctx> Workspace<'gctx> {
                 }
             }
         }
-        match self.gctx().get::<CargoResolverConfig>("resolver") {
-            Ok(CargoResolverConfig {
-                incompatible_rust_versions: Some(incompatible_rust_versions),
-            }) => {
-                if self.gctx().cli_unstable().msrv_policy {
-                    self.resolve_honors_rust_version =
-                        incompatible_rust_versions == IncompatibleRustVersions::Fallback;
-                } else {
-                    self.gctx()
-                        .shell()
-                        .warn("ignoring `resolver` config table without `-Zmsrv-policy`")?;
-                }
-            }
-            Ok(CargoResolverConfig {
-                incompatible_rust_versions: None,
-            }) => {}
-            Err(err) => {
-                if self.gctx().cli_unstable().msrv_policy {
-                    return Err(err);
-                } else {
-                    self.gctx()
-                        .shell()
-                        .warn("ignoring `resolver` config table without `-Zmsrv-policy`")?;
-                }
-            }
+        if let CargoResolverConfig {
+            incompatible_rust_versions: Some(incompatible_rust_versions),
+        } = self.gctx().get::<CargoResolverConfig>("resolver")?
+        {
+            self.resolve_honors_rust_version =
+                incompatible_rust_versions == IncompatibleRustVersions::Fallback;
         }
 
         Ok(())

tests/testsuite/cargo_add/rust_version_ignore/mod.rs

@@ -20,13 +20,11 @@ fn case() {
     let cwd = &project_root;
 
     snapbox::cmd::Command::cargo_ui()
-        .arg("-Zmsrv-policy")
         .arg("add")
         .arg("--ignore-rust-version")
         .arg_line("rust-version-user")
         .current_dir(cwd)
         .env("CARGO_RESOLVER_INCOMPATIBLE_RUST_VERSIONS", "fallback")
-        .masquerade_as_nightly_cargo(&["msrv-policy"])
         .assert()
         .code(0)
         .stdout_eq(str![""])

tests/testsuite/cargo_add/rust_version_incompatible/mod.rs

@@ -23,12 +23,10 @@ fn case() {
     let cwd = &project_root;
 
     snapbox::cmd::Command::cargo_ui()
-        .arg("-Zmsrv-policy")
         .arg("add")
         .arg_line("rust-version-user")
         .current_dir(cwd)
         .env("CARGO_RESOLVER_INCOMPATIBLE_RUST_VERSIONS", "fallback")
-        .masquerade_as_nightly_cargo(&["msrv-policy"])
         .assert()
         .failure()
         .stdout_eq(str![""])

tests/testsuite/cargo_add/rust_version_latest/mod.rs

@@ -20,12 +20,10 @@ fn case() {
     let cwd = &project_root;
 
     snapbox::cmd::Command::cargo_ui()
-        .arg("-Zmsrv-policy")
         .arg("add")
         .arg_line("rust-version-user")
         .current_dir(cwd)
         .env("CARGO_RESOLVER_INCOMPATIBLE_RUST_VERSIONS", "fallback")
-        .masquerade_as_nightly_cargo(&["msrv-policy"])
         .assert()
         .success()
         .stdout_eq(str![""])

tests/testsuite/cargo_add/rust_version_older/mod.rs

@@ -20,12 +20,10 @@ fn case() {
     let cwd = &project_root;
 
     snapbox::cmd::Command::cargo_ui()
-        .arg("-Zmsrv-policy")
         .arg("add")
         .arg_line("rust-version-user")
         .current_dir(cwd)
         .env("CARGO_RESOLVER_INCOMPATIBLE_RUST_VERSIONS", "fallback")
-        .masquerade_as_nightly_cargo(&["msrv-policy"])
         .assert()
         .success()
         .stdout_eq(str![""])

tests/testsuite/cargo_add/rustc_ignore/mod.rs

@@ -23,13 +23,11 @@ fn case() {
     let cwd = &project_root;
 
     snapbox::cmd::Command::cargo_ui()
-        .arg("-Zmsrv-policy")
         .arg("add")
         .arg("--ignore-rust-version")
         .arg_line("rust-version-user")
         .current_dir(cwd)
         .env("CARGO_RESOLVER_INCOMPATIBLE_RUST_VERSIONS", "fallback")
-        .masquerade_as_nightly_cargo(&["msrv-policy"])
         .assert()
         .code(0)
         .stdout_eq(str![""])

tests/testsuite/cargo_add/rustc_incompatible/mod.rs

@@ -17,12 +17,10 @@ fn case() {
     let cwd = &project_root;
 
     snapbox::cmd::Command::cargo_ui()
-        .arg("-Zmsrv-policy")
         .arg("add")
         .arg_line("rust-version-user")
         .current_dir(cwd)
         .env("CARGO_RESOLVER_INCOMPATIBLE_RUST_VERSIONS", "fallback")
-        .masquerade_as_nightly_cargo(&["msrv-policy"])
         .assert()
         .failure()
         .stdout_eq(str![""])

tests/testsuite/cargo_add/rustc_latest/mod.rs

@@ -23,12 +23,10 @@ fn case() {
     let cwd = &project_root;
 
     snapbox::cmd::Command::cargo_ui()
-        .arg("-Zmsrv-policy")
         .arg("add")
         .arg_line("rust-version-user")
         .current_dir(cwd)
         .env("CARGO_RESOLVER_INCOMPATIBLE_RUST_VERSIONS", "fallback")
-        .masquerade_as_nightly_cargo(&["msrv-policy"])
         .assert()
         .success()
         .stdout_eq(str![""])

tests/testsuite/cargo_add/rustc_older/mod.rs

@@ -23,12 +23,10 @@ fn case() {
     let cwd = &project_root;
 
     snapbox::cmd::Command::cargo_ui()
-        .arg("-Zmsrv-policy")
         .arg("add")
         .arg_line("rust-version-user")
         .current_dir(cwd)
         .env("CARGO_RESOLVER_INCOMPATIBLE_RUST_VERSIONS", "fallback")
-        .masquerade_as_nightly_cargo(&["msrv-policy"])
         .assert()
         .success()
         .stdout_eq(str![""])