diff --git a/src/bin/cargo/cli.rs b/src/bin/cargo/cli.rs
index a21030f0141..0a66a2382e9 100644
--- a/src/bin/cargo/cli.rs
+++ b/src/bin/cargo/cli.rs
@@ -1,6 +1,7 @@
 use anyhow::{anyhow, Context as _};
 use cargo::core::shell::Shell;
 use cargo::core::{features, CliUnstable};
+use cargo::util::config::WarningHandling;
 use cargo::{self, drop_print, drop_println, CargoResult, CliResult, Config};
 use clap::{builder::UnknownArgumentValueParser, Arg, ArgMatches};
 use itertools::Itertools;
@@ -181,7 +182,9 @@ Run with 'cargo -Z [FLAG] [COMMAND]'",
     config_configure(config, &expanded_args, subcommand_args, global_args, &exec)?;
     super::init_git(config);
 
-    exec.exec(config, subcommand_args)
+    let result = exec.exec(config, subcommand_args);
+    config.shell().error_for_warnings()?;
+    result
 }
 
 pub fn get_version_string(is_verbose: bool) -> String {
@@ -394,6 +397,13 @@ fn config_configure(
     let frozen = args.flag("frozen") || global_args.frozen;
     let locked = args.flag("locked") || global_args.locked;
     let offline = args.flag("offline") || global_args.offline;
+    let warnings = match args.get_one::<String>("warnings").map(String::as_str) {
+        Some("ignore") => Some(WarningHandling::Ignore),
+        Some("warn") => Some(WarningHandling::Warn),
+        Some("error") => Some(WarningHandling::Error),
+        None => None,
+        _ => unreachable!(),
+    };
     let mut unstable_flags = global_args.unstable_flags;
     if let Some(values) = args.get_many::<String>("unstable-features") {
         unstable_flags.extend(values.cloned());
@@ -405,6 +415,7 @@ fn config_configure(
     config.configure(
         verbose,
         quiet,
+        warnings,
         color,
         frozen,
         locked,
@@ -595,6 +606,11 @@ See '<cyan,bold>cargo help</> <cyan><<command>></>' for more information on a sp
                 .value_name("WHEN")
                 .global(true),
         )
+        .arg(
+            opt("warnings", "Warning behavior")
+                .value_parser(["error", "warn", "ignore"])
+                .global(true),
+        )
         .arg(
             Arg::new("directory")
                 .help("Change to DIRECTORY before doing anything (nightly-only)")
diff --git a/src/cargo/core/compiler/job_queue/mod.rs b/src/cargo/core/compiler/job_queue/mod.rs
index e39fe184dfa..f4050e1ef32 100644
--- a/src/cargo/core/compiler/job_queue/mod.rs
+++ b/src/cargo/core/compiler/job_queue/mod.rs
@@ -140,6 +140,7 @@ use crate::core::compiler::future_incompat::{
 };
 use crate::core::resolver::ResolveBehavior;
 use crate::core::{PackageId, Shell, TargetKind};
+use crate::util::config::WarningHandling;
 use crate::util::diagnostic_server::{self, DiagnosticPrinter};
 use crate::util::errors::AlreadyPrintedError;
 use crate::util::machine_message::{self, Message as _};
@@ -314,8 +315,10 @@ impl<'cfg> DiagDedupe<'cfg> {
             return Ok(false);
         }
         let mut shell = self.config.shell();
-        shell.print_ansi_stderr(diag.as_bytes())?;
-        shell.err().write_all(b"\n")?;
+        if shell.warnings() != WarningHandling::Ignore {
+            shell.print_ansi_stderr(diag.as_bytes())?;
+            shell.err().write_all(b"\n")?;
+        }
         Ok(true)
     }
 }
diff --git a/src/cargo/core/shell.rs b/src/cargo/core/shell.rs
index a9b9e84afcd..1fc9dd966ec 100644
--- a/src/cargo/core/shell.rs
+++ b/src/cargo/core/shell.rs
@@ -5,6 +5,7 @@ use std::io::IsTerminal;
 use anstream::AutoStream;
 use anstyle::Style;
 
+use crate::util::config::WarningHandling;
 use crate::util::errors::CargoResult;
 use crate::util::style::*;
 
@@ -57,6 +58,10 @@ pub struct Shell {
     /// Flag that indicates the current line needs to be cleared before
     /// printing. Used when a progress bar is currently displayed.
     needs_clear: bool,
+    /// How warning should be handled.
+    warnings: WarningHandling,
+    /// The number of warnings so far.
+    warning_count: usize,
 }
 
 impl fmt::Debug for Shell {
@@ -115,6 +120,8 @@ impl Shell {
             },
             verbosity: Verbosity::Verbose,
             needs_clear: false,
+            warnings: WarningHandling::Warn,
+            warning_count: 0,
         }
     }
 
@@ -124,6 +131,8 @@ impl Shell {
             output: ShellOut::Write(AutoStream::never(out)), // strip all formatting on write
             verbosity: Verbosity::Verbose,
             needs_clear: false,
+            warnings: WarningHandling::Warn,
+            warning_count: 0,
         }
     }
 
@@ -263,10 +272,13 @@ impl Shell {
 
     /// Prints an amber 'warning' message.
     pub fn warn<T: fmt::Display>(&mut self, message: T) -> CargoResult<()> {
-        match self.verbosity {
-            Verbosity::Quiet => Ok(()),
-            _ => self.print(&"warning", Some(&message), &WARN, false),
+        self.warning_count += 1;
+        if matches!(self.verbosity, Verbosity::Quiet)
+            || matches!(self.warnings, WarningHandling::Ignore)
+        {
+            return Ok(());
         }
+        self.print(&"warning", Some(&message), &WARN, false)
     }
 
     /// Prints a cyan 'note' message.
@@ -284,6 +296,31 @@ impl Shell {
         self.verbosity
     }
 
+    /// Updates how warnings are handled.
+    pub fn set_warnings(&mut self, warnings: WarningHandling) {
+        self.warnings = warnings;
+    }
+
+    /// Gets the warning handling behavior.
+    pub fn warnings(&self) -> WarningHandling {
+        self.warnings
+    }
+
+    /// Emit an error if any warnings have been seen.
+    pub fn error_for_warnings(&self) -> CargoResult<()> {
+        if self.warning_count > 0 && self.warnings == WarningHandling::Error {
+            let quiet_note = if self.verbosity == Verbosity::Quiet {
+                " (note that verbosity is set to quiet, which may hide warnings)"
+            } else {
+                ""
+            };
+            anyhow::bail!(
+                "warnings detected and warnings are disallowed by configuration{quiet_note}"
+            );
+        }
+        Ok(())
+    }
+
     /// Updates the color choice (always, never, or auto) from a string..
     pub fn set_color_choice(&mut self, color: Option<&str>) -> CargoResult<()> {
         if let ShellOut::Stream {
diff --git a/src/cargo/util/config/mod.rs b/src/cargo/util/config/mod.rs
index 039cf7cd04f..bc31878c2b6 100644
--- a/src/cargo/util/config/mod.rs
+++ b/src/cargo/util/config/mod.rs
@@ -158,6 +158,16 @@ pub struct CredentialCacheValue {
     pub operation_independent: bool,
 }
 
+/// Whether warnings should warn, be ignored, or cause an error.
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Deserialize, Default)]
+#[serde(rename_all = "kebab-case")]
+pub enum WarningHandling {
+    #[default]
+    Warn,
+    Ignore,
+    Error,
+}
+
 /// Configuration information for cargo. This is not specific to a build, it is information
 /// relating to cargo itself.
 #[derive(Debug)]
@@ -971,6 +981,7 @@ impl Config {
         &mut self,
         verbose: u32,
         quiet: bool,
+        warnings: Option<WarningHandling>,
         color: Option<&str>,
         frozen: bool,
         locked: bool,
@@ -1032,6 +1043,8 @@ impl Config {
 
         self.shell().set_verbosity(verbosity);
         self.shell().set_color_choice(color)?;
+        self.shell()
+            .set_warnings(warnings.or_else(|| term.warnings).unwrap_or_default());
         self.progress_config = term.progress.unwrap_or_default();
         self.extra_verbose = extra_verbose;
         self.frozen = frozen;
@@ -2563,6 +2576,7 @@ struct TermConfig {
     #[serde(default)]
     #[serde(deserialize_with = "progress_or_string")]
     progress: Option<ProgressConfig>,
+    warnings: Option<WarningHandling>,
 }
 
 #[derive(Debug, Default, Deserialize)]
diff --git a/src/doc/man/includes/options-display.md b/src/doc/man/includes/options-display.md
index 917dac49cc0..e775c508a89 100644
--- a/src/doc/man/includes/options-display.md
+++ b/src/doc/man/includes/options-display.md
@@ -22,3 +22,14 @@ Control when colored output is used. Valid values:
 May also be specified with the `term.color`
 [config value](../reference/config.html).
 {{/option}}
+
+{{#option "`--warnings`"}}
+Overrides how warnings are handled. Valid values:
+
+* `warn` (default): warnings are displayed and do not fail the operation.
+* `error`: if any warnings are encountered an error will be emitted at the of the operation.
+* `ignore`: warnings will be silently ignored.
+
+May also be specified with the `term.warnings`
+[config value](../reference/config.html).
+{{/option}}
diff --git a/src/doc/src/reference/config.md b/src/doc/src/reference/config.md
index 9ef42f68f4d..5414df917e2 100644
--- a/src/doc/src/reference/config.md
+++ b/src/doc/src/reference/config.md
@@ -1257,6 +1257,19 @@ Controls whether or not extra detailed messages are displayed by Cargo.
 Specifying the `--quiet` flag will override and disable verbose output.
 Specifying the `--verbose` flag will override and force verbose output.
 
+#### `term.warnings`
+* Type: string
+* Default: "warn"
+* Environment: `CARGO_TERM_WARNINGS`
+
+Overrides how warnings are handled, including warnings that come from `rustc`.
+
+The `--warnings=` CLI option overrides this configuration value.
+
+* `warn` (default): warnings are displayed and do not fail the operation.
+* `error`: if any warnings are encountered an error will be emitted at the of the operation.
+* `ignore`: warnings will be silently ignored.
+
 #### `term.color`
 * Type: string
 * Default: "auto"
diff --git a/tests/testsuite/cargo/help/stdout.log b/tests/testsuite/cargo/help/stdout.log
index e15848ab784..8de241c08fc 100644
--- a/tests/testsuite/cargo/help/stdout.log
+++ b/tests/testsuite/cargo/help/stdout.log
@@ -4,19 +4,20 @@ Usage: cargo [..][OPTIONS] [COMMAND]
        cargo [..][OPTIONS] -Zscript <MANIFEST_RS> [ARGS]...
 
 Options:
-  -V, --version             Print version info and exit
-      --list                List installed commands
-      --explain <CODE>      Provide a detailed explanation of a rustc error message
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-  -q, --quiet               Do not print cargo log messages
-      --color <WHEN>        Coloring: auto, always, never
-  -C <DIRECTORY>            Change to DIRECTORY before doing anything (nightly-only)
-      --frozen              Require Cargo.lock and cache are up to date
-      --locked              Require Cargo.lock is up to date
-      --offline             Run without accessing the network
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+  -V, --version              Print version info and exit
+      --list                 List installed commands
+      --explain <CODE>       Provide a detailed explanation of a rustc error message
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+  -q, --quiet                Do not print cargo log messages
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+  -C <DIRECTORY>             Change to DIRECTORY before doing anything (nightly-only)
+      --frozen               Require Cargo.lock and cache are up to date
+      --locked               Require Cargo.lock is up to date
+      --offline              Run without accessing the network
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Commands:
     build, b    Compile the current package
diff --git a/tests/testsuite/cargo_add/help/stdout.log b/tests/testsuite/cargo_add/help/stdout.log
index cf2a913132d..4384f2bdb87 100644
--- a/tests/testsuite/cargo_add/help/stdout.log
+++ b/tests/testsuite/cargo_add/help/stdout.log
@@ -54,6 +54,11 @@ Options:
       --color <WHEN>
           Coloring: auto, always, never
 
+      --warnings <warnings>
+          Warning behavior
+          
+          [possible values: error, warn, ignore]
+
       --config <KEY=VALUE>
           Override a configuration value
 
diff --git a/tests/testsuite/cargo_bench/help/stdout.log b/tests/testsuite/cargo_bench/help/stdout.log
index a310f73aa28..df76a131b81 100644
--- a/tests/testsuite/cargo_bench/help/stdout.log
+++ b/tests/testsuite/cargo_bench/help/stdout.log
@@ -14,6 +14,7 @@ Options:
   -q, --quiet                 Do not print cargo log messages
   -v, --verbose...            Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>          Coloring: auto, always, never
+      --warnings <warnings>   Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>    Override a configuration value
   -Z <FLAG>                   Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for
                               details
diff --git a/tests/testsuite/cargo_build/help/stdout.log b/tests/testsuite/cargo_build/help/stdout.log
index 56b934cd168..c6f56a60add 100644
--- a/tests/testsuite/cargo_build/help/stdout.log
+++ b/tests/testsuite/cargo_build/help/stdout.log
@@ -9,6 +9,7 @@ Options:
   -q, --quiet                   Do not print cargo log messages
   -v, --verbose...              Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>            Coloring: auto, always, never
+      --warnings <warnings>     Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>      Override a configuration value
   -Z <FLAG>                     Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for
                                 details
diff --git a/tests/testsuite/cargo_check/help/stdout.log b/tests/testsuite/cargo_check/help/stdout.log
index 92d44a6ded2..615f2698c5d 100644
--- a/tests/testsuite/cargo_check/help/stdout.log
+++ b/tests/testsuite/cargo_check/help/stdout.log
@@ -9,6 +9,7 @@ Options:
   -q, --quiet                   Do not print cargo log messages
   -v, --verbose...              Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>            Coloring: auto, always, never
+      --warnings <warnings>     Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>      Override a configuration value
   -Z <FLAG>                     Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for
                                 details
diff --git a/tests/testsuite/cargo_clean/help/stdout.log b/tests/testsuite/cargo_clean/help/stdout.log
index 6e9e82772f1..665872fbaa7 100644
--- a/tests/testsuite/cargo_clean/help/stdout.log
+++ b/tests/testsuite/cargo_clean/help/stdout.log
@@ -3,14 +3,15 @@ Remove artifacts that cargo has generated in the past
 Usage: cargo[EXE] clean [OPTIONS]
 
 Options:
-      --doc                 Whether or not to clean just the documentation directory
-  -q, --quiet               Do not print cargo log messages
-  -n, --dry-run             Display what would be deleted without deleting anything
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-      --color <WHEN>        Coloring: auto, always, never
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+      --doc                  Whether or not to clean just the documentation directory
+  -q, --quiet                Do not print cargo log messages
+  -n, --dry-run              Display what would be deleted without deleting anything
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Package Selection:
   -p, --package [<SPEC>]  Package to clean artifacts for
diff --git a/tests/testsuite/cargo_config/help/stdout.log b/tests/testsuite/cargo_config/help/stdout.log
index 50caca72a4c..5bb9d189329 100644
--- a/tests/testsuite/cargo_config/help/stdout.log
+++ b/tests/testsuite/cargo_config/help/stdout.log
@@ -6,11 +6,12 @@ Commands:
   get  
 
 Options:
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-      --color <WHEN>        Coloring: auto, always, never
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Manifest Options:
       --frozen   Require Cargo.lock and cache are up to date
diff --git a/tests/testsuite/cargo_doc/help/stdout.log b/tests/testsuite/cargo_doc/help/stdout.log
index 8ff5f9b72a7..ed635e57f7c 100644
--- a/tests/testsuite/cargo_doc/help/stdout.log
+++ b/tests/testsuite/cargo_doc/help/stdout.log
@@ -11,6 +11,7 @@ Options:
   -q, --quiet                   Do not print cargo log messages
   -v, --verbose...              Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>            Coloring: auto, always, never
+      --warnings <warnings>     Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>      Override a configuration value
   -Z <FLAG>                     Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for
                                 details
diff --git a/tests/testsuite/cargo_fetch/help/stdout.log b/tests/testsuite/cargo_fetch/help/stdout.log
index 32f29f1b39a..76685295585 100644
--- a/tests/testsuite/cargo_fetch/help/stdout.log
+++ b/tests/testsuite/cargo_fetch/help/stdout.log
@@ -3,12 +3,13 @@ Fetch dependencies of a package from the network
 Usage: cargo[EXE] fetch [OPTIONS]
 
 Options:
-  -q, --quiet               Do not print cargo log messages
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-      --color <WHEN>        Coloring: auto, always, never
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+  -q, --quiet                Do not print cargo log messages
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Compilation Options:
       --target [<TRIPLE>]  Fetch dependencies for the target triple
diff --git a/tests/testsuite/cargo_fix/help/stdout.log b/tests/testsuite/cargo_fix/help/stdout.log
index dbbd11b7752..efe739d5b4a 100644
--- a/tests/testsuite/cargo_fix/help/stdout.log
+++ b/tests/testsuite/cargo_fix/help/stdout.log
@@ -14,6 +14,7 @@ Options:
   -q, --quiet                 Do not print cargo log messages
   -v, --verbose...            Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>          Coloring: auto, always, never
+      --warnings <warnings>   Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>    Override a configuration value
   -Z <FLAG>                   Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for
                               details
diff --git a/tests/testsuite/cargo_generate_lockfile/help/stdout.log b/tests/testsuite/cargo_generate_lockfile/help/stdout.log
index 07eff888a20..2acf36ef9bc 100644
--- a/tests/testsuite/cargo_generate_lockfile/help/stdout.log
+++ b/tests/testsuite/cargo_generate_lockfile/help/stdout.log
@@ -3,12 +3,13 @@ Generate the lockfile for a package
 Usage: cargo[EXE] generate-lockfile [OPTIONS]
 
 Options:
-  -q, --quiet               Do not print cargo log messages
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-      --color <WHEN>        Coloring: auto, always, never
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+  -q, --quiet                Do not print cargo log messages
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Manifest Options:
       --manifest-path <PATH>  Path to Cargo.toml
diff --git a/tests/testsuite/cargo_help/help/stdout.log b/tests/testsuite/cargo_help/help/stdout.log
index a03946b45ff..0fe54c2cfd7 100644
--- a/tests/testsuite/cargo_help/help/stdout.log
+++ b/tests/testsuite/cargo_help/help/stdout.log
@@ -6,11 +6,12 @@ Arguments:
   [COMMAND]  
 
 Options:
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-      --color <WHEN>        Coloring: auto, always, never
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Manifest Options:
       --frozen   Require Cargo.lock and cache are up to date
diff --git a/tests/testsuite/cargo_init/help/stdout.log b/tests/testsuite/cargo_init/help/stdout.log
index 588b45ccf4a..b3782a54292 100644
--- a/tests/testsuite/cargo_init/help/stdout.log
+++ b/tests/testsuite/cargo_init/help/stdout.log
@@ -18,6 +18,7 @@ Options:
   -q, --quiet                Do not print cargo log messages
   -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>   Override a configuration value
   -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
   -h, --help                 Print help
diff --git a/tests/testsuite/cargo_install/help/stdout.log b/tests/testsuite/cargo_install/help/stdout.log
index 5e3458d37a8..c82156acfe5 100644
--- a/tests/testsuite/cargo_install/help/stdout.log
+++ b/tests/testsuite/cargo_install/help/stdout.log
@@ -24,6 +24,7 @@ Options:
       --debug                 Build in debug mode (with the 'dev' profile) instead of release mode
   -v, --verbose...            Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>          Coloring: auto, always, never
+      --warnings <warnings>   Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>    Override a configuration value
   -Z <FLAG>                   Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for
                               details
diff --git a/tests/testsuite/cargo_locate_project/help/stdout.log b/tests/testsuite/cargo_locate_project/help/stdout.log
index 1c6ea7b2561..6b349ea3702 100644
--- a/tests/testsuite/cargo_locate_project/help/stdout.log
+++ b/tests/testsuite/cargo_locate_project/help/stdout.log
@@ -8,6 +8,7 @@ Options:
   -q, --quiet                 Do not print cargo log messages
   -v, --verbose...            Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>          Coloring: auto, always, never
+      --warnings <warnings>   Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>    Override a configuration value
   -Z <FLAG>                   Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for
                               details
diff --git a/tests/testsuite/cargo_login/help/stdout.log b/tests/testsuite/cargo_login/help/stdout.log
index e0d5e7e69ce..de5e518e610 100644
--- a/tests/testsuite/cargo_login/help/stdout.log
+++ b/tests/testsuite/cargo_login/help/stdout.log
@@ -11,6 +11,7 @@ Options:
   -q, --quiet                Do not print cargo log messages
   -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>   Override a configuration value
   -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
   -h, --help                 Print help
diff --git a/tests/testsuite/cargo_logout/help/stdout.log b/tests/testsuite/cargo_logout/help/stdout.log
index fe328d765a9..117f256c34b 100644
--- a/tests/testsuite/cargo_logout/help/stdout.log
+++ b/tests/testsuite/cargo_logout/help/stdout.log
@@ -7,6 +7,7 @@ Options:
   -q, --quiet                Do not print cargo log messages
   -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>   Override a configuration value
   -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
   -h, --help                 Print help
diff --git a/tests/testsuite/cargo_metadata/help/stdout.log b/tests/testsuite/cargo_metadata/help/stdout.log
index 939fc40c9c0..3ed8710b740 100644
--- a/tests/testsuite/cargo_metadata/help/stdout.log
+++ b/tests/testsuite/cargo_metadata/help/stdout.log
@@ -11,6 +11,7 @@ Options:
   -q, --quiet                     Do not print cargo log messages
   -v, --verbose...                Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>              Coloring: auto, always, never
+      --warnings <warnings>       Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>        Override a configuration value
   -Z <FLAG>                       Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for
                                   details
diff --git a/tests/testsuite/cargo_new/help/stdout.log b/tests/testsuite/cargo_new/help/stdout.log
index 3df5eceb87e..f55498b22a1 100644
--- a/tests/testsuite/cargo_new/help/stdout.log
+++ b/tests/testsuite/cargo_new/help/stdout.log
@@ -18,6 +18,7 @@ Options:
   -q, --quiet                Do not print cargo log messages
   -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>   Override a configuration value
   -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
   -h, --help                 Print help
diff --git a/tests/testsuite/cargo_owner/help/stdout.log b/tests/testsuite/cargo_owner/help/stdout.log
index 110df8e9afb..543f1670f35 100644
--- a/tests/testsuite/cargo_owner/help/stdout.log
+++ b/tests/testsuite/cargo_owner/help/stdout.log
@@ -15,6 +15,7 @@ Options:
   -q, --quiet                Do not print cargo log messages
   -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>   Override a configuration value
   -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
   -h, --help                 Print help
diff --git a/tests/testsuite/cargo_package/help/stdout.log b/tests/testsuite/cargo_package/help/stdout.log
index 5079c2a6fa3..7b2b2124fc3 100644
--- a/tests/testsuite/cargo_package/help/stdout.log
+++ b/tests/testsuite/cargo_package/help/stdout.log
@@ -3,16 +3,17 @@ Assemble the local package into a distributable tarball
 Usage: cargo[EXE] package [OPTIONS]
 
 Options:
-  -l, --list                Print files included in a package without making one
-      --no-verify           Don't verify the contents by building them
-      --no-metadata         Ignore warnings about a lack of human-usable metadata
-      --allow-dirty         Allow dirty working directories to be packaged
-  -q, --quiet               Do not print cargo log messages
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-      --color <WHEN>        Coloring: auto, always, never
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+  -l, --list                 Print files included in a package without making one
+      --no-verify            Don't verify the contents by building them
+      --no-metadata          Ignore warnings about a lack of human-usable metadata
+      --allow-dirty          Allow dirty working directories to be packaged
+  -q, --quiet                Do not print cargo log messages
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Package Selection:
   -p, --package [<SPEC>]  Package(s) to assemble
diff --git a/tests/testsuite/cargo_pkgid/help/stdout.log b/tests/testsuite/cargo_pkgid/help/stdout.log
index 5971e88dc6f..229e74553d0 100644
--- a/tests/testsuite/cargo_pkgid/help/stdout.log
+++ b/tests/testsuite/cargo_pkgid/help/stdout.log
@@ -6,12 +6,13 @@ Arguments:
   [SPEC]  
 
 Options:
-  -q, --quiet               Do not print cargo log messages
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-      --color <WHEN>        Coloring: auto, always, never
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+  -q, --quiet                Do not print cargo log messages
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Package Selection:
   -p, --package [<SPEC>]  Argument to get the package ID specifier for
diff --git a/tests/testsuite/cargo_publish/help/stdout.log b/tests/testsuite/cargo_publish/help/stdout.log
index df2594fb462..14ed774e91e 100644
--- a/tests/testsuite/cargo_publish/help/stdout.log
+++ b/tests/testsuite/cargo_publish/help/stdout.log
@@ -12,6 +12,7 @@ Options:
   -q, --quiet                Do not print cargo log messages
   -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>   Override a configuration value
   -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
   -h, --help                 Print help
diff --git a/tests/testsuite/cargo_read_manifest/help/stdout.log b/tests/testsuite/cargo_read_manifest/help/stdout.log
index 83db5413d92..f5d3cabc426 100644
--- a/tests/testsuite/cargo_read_manifest/help/stdout.log
+++ b/tests/testsuite/cargo_read_manifest/help/stdout.log
@@ -5,12 +5,13 @@ Deprecated, use `cargo metadata --no-deps` instead.
 Usage: cargo[EXE] read-manifest [OPTIONS]
 
 Options:
-  -q, --quiet               Do not print cargo log messages
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-      --color <WHEN>        Coloring: auto, always, never
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+  -q, --quiet                Do not print cargo log messages
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Manifest Options:
       --manifest-path <PATH>  Path to Cargo.toml
diff --git a/tests/testsuite/cargo_remove/help/stdout.log b/tests/testsuite/cargo_remove/help/stdout.log
index 47d2c87adae..72a9c11ec07 100644
--- a/tests/testsuite/cargo_remove/help/stdout.log
+++ b/tests/testsuite/cargo_remove/help/stdout.log
@@ -6,13 +6,14 @@ Arguments:
   <DEP_ID>...  Dependencies to be removed
 
 Options:
-  -n, --dry-run             Don't actually write the manifest
-  -q, --quiet               Do not print cargo log messages
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-      --color <WHEN>        Coloring: auto, always, never
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+  -n, --dry-run              Don't actually write the manifest
+  -q, --quiet                Do not print cargo log messages
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Section:
       --dev              Remove from dev-dependencies
diff --git a/tests/testsuite/cargo_report/help/stdout.log b/tests/testsuite/cargo_report/help/stdout.log
index 67819de55c4..89981a58436 100644
--- a/tests/testsuite/cargo_report/help/stdout.log
+++ b/tests/testsuite/cargo_report/help/stdout.log
@@ -6,11 +6,12 @@ Commands:
   future-incompatibilities  Reports any crates which will eventually stop compiling
 
 Options:
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-      --color <WHEN>        Coloring: auto, always, never
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Manifest Options:
       --frozen   Require Cargo.lock and cache are up to date
diff --git a/tests/testsuite/cargo_run/help/stdout.log b/tests/testsuite/cargo_run/help/stdout.log
index 97c13382a67..2848758a488 100644
--- a/tests/testsuite/cargo_run/help/stdout.log
+++ b/tests/testsuite/cargo_run/help/stdout.log
@@ -11,6 +11,7 @@ Options:
   -q, --quiet                 Do not print cargo log messages
   -v, --verbose...            Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>          Coloring: auto, always, never
+      --warnings <warnings>   Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>    Override a configuration value
   -Z <FLAG>                   Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for
                               details
diff --git a/tests/testsuite/cargo_rustc/help/stdout.log b/tests/testsuite/cargo_rustc/help/stdout.log
index 8d184dc0629..03f0789377e 100644
--- a/tests/testsuite/cargo_rustc/help/stdout.log
+++ b/tests/testsuite/cargo_rustc/help/stdout.log
@@ -14,6 +14,7 @@ Options:
   -q, --quiet                    Do not print cargo log messages
   -v, --verbose...               Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>             Coloring: auto, always, never
+      --warnings <warnings>      Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>       Override a configuration value
   -Z <FLAG>                      Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for
                                  details
diff --git a/tests/testsuite/cargo_rustdoc/help/stdout.log b/tests/testsuite/cargo_rustdoc/help/stdout.log
index 8d4415cbb63..6eba3384282 100644
--- a/tests/testsuite/cargo_rustdoc/help/stdout.log
+++ b/tests/testsuite/cargo_rustdoc/help/stdout.log
@@ -12,6 +12,7 @@ Options:
   -q, --quiet                 Do not print cargo log messages
   -v, --verbose...            Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>          Coloring: auto, always, never
+      --warnings <warnings>   Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>    Override a configuration value
   -Z <FLAG>                   Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for
                               details
diff --git a/tests/testsuite/cargo_search/help/stdout.log b/tests/testsuite/cargo_search/help/stdout.log
index 9cc508bba9c..baf1828399e 100644
--- a/tests/testsuite/cargo_search/help/stdout.log
+++ b/tests/testsuite/cargo_search/help/stdout.log
@@ -12,6 +12,7 @@ Options:
   -q, --quiet                Do not print cargo log messages
   -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>   Override a configuration value
   -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
   -h, --help                 Print help
diff --git a/tests/testsuite/cargo_test/help/stdout.log b/tests/testsuite/cargo_test/help/stdout.log
index d69fcb0edb5..6cf80350223 100644
--- a/tests/testsuite/cargo_test/help/stdout.log
+++ b/tests/testsuite/cargo_test/help/stdout.log
@@ -16,6 +16,7 @@ Options:
   -q, --quiet                   Display one character per test instead of one line
   -v, --verbose...              Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>            Coloring: auto, always, never
+      --warnings <warnings>     Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>      Override a configuration value
   -Z <FLAG>                     Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for
                                 details
diff --git a/tests/testsuite/cargo_tree/help/stdout.log b/tests/testsuite/cargo_tree/help/stdout.log
index 4170583a854..9d6a9dca18b 100644
--- a/tests/testsuite/cargo_tree/help/stdout.log
+++ b/tests/testsuite/cargo_tree/help/stdout.log
@@ -3,24 +3,25 @@ Display a tree visualization of a dependency graph
 Usage: cargo[EXE] tree [OPTIONS]
 
 Options:
-  -q, --quiet               Do not print cargo log messages
-  -e, --edges <KINDS>       The kinds of dependencies to display (features, normal, build, dev, all,
-                            no-normal, no-build, no-dev, no-proc-macro)
-  -i, --invert [<SPEC>]     Invert the tree direction and focus on the given package
-      --prune <SPEC>        Prune the given package from the display of the dependency tree
-      --depth <DEPTH>       Maximum display depth of the dependency tree
-      --prefix <PREFIX>     Change the prefix (indentation) of how each entry is displayed [default:
-                            indent] [possible values: depth, indent, none]
-      --no-dedupe           Do not de-duplicate (repeats all shared dependencies)
-  -d, --duplicates          Show only dependencies which come in multiple versions (implies -i)
-      --charset <CHARSET>   Character set to use in output [default: utf8] [possible values: utf8,
-                            ascii]
-  -f, --format <FORMAT>     Format string used for printing dependencies [default: {p}]
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-      --color <WHEN>        Coloring: auto, always, never
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+  -q, --quiet                Do not print cargo log messages
+  -e, --edges <KINDS>        The kinds of dependencies to display (features, normal, build, dev,
+                             all, no-normal, no-build, no-dev, no-proc-macro)
+  -i, --invert [<SPEC>]      Invert the tree direction and focus on the given package
+      --prune <SPEC>         Prune the given package from the display of the dependency tree
+      --depth <DEPTH>        Maximum display depth of the dependency tree
+      --prefix <PREFIX>      Change the prefix (indentation) of how each entry is displayed
+                             [default: indent] [possible values: depth, indent, none]
+      --no-dedupe            Do not de-duplicate (repeats all shared dependencies)
+  -d, --duplicates           Show only dependencies which come in multiple versions (implies -i)
+      --charset <CHARSET>    Character set to use in output [default: utf8] [possible values: utf8,
+                             ascii]
+  -f, --format <FORMAT>      Format string used for printing dependencies [default: {p}]
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Package Selection:
   -p, --package [<SPEC>]  Package to be used as the root of the tree
diff --git a/tests/testsuite/cargo_uninstall/help/stdout.log b/tests/testsuite/cargo_uninstall/help/stdout.log
index efdf11c039a..e570eb49b73 100644
--- a/tests/testsuite/cargo_uninstall/help/stdout.log
+++ b/tests/testsuite/cargo_uninstall/help/stdout.log
@@ -6,13 +6,14 @@ Arguments:
   [SPEC]...  
 
 Options:
-      --root <DIR>          Directory to uninstall packages from
-  -q, --quiet               Do not print cargo log messages
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-      --color <WHEN>        Coloring: auto, always, never
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+      --root <DIR>           Directory to uninstall packages from
+  -q, --quiet                Do not print cargo log messages
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Package Selection:
   -p, --package [<SPEC>]  Package to uninstall
diff --git a/tests/testsuite/cargo_update/help/stdout.log b/tests/testsuite/cargo_update/help/stdout.log
index 92caeb65601..5eac83fc671 100644
--- a/tests/testsuite/cargo_update/help/stdout.log
+++ b/tests/testsuite/cargo_update/help/stdout.log
@@ -3,15 +3,16 @@ Update dependencies as recorded in the local lock file
 Usage: cargo[EXE] update [OPTIONS] [SPEC]...
 
 Options:
-  -n, --dry-run             Don't actually write the lockfile
-      --recursive           Force updating all dependencies of [SPEC]... as well
-      --precise <PRECISE>   Update [SPEC] to exactly PRECISE
-  -q, --quiet               Do not print cargo log messages
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-      --color <WHEN>        Coloring: auto, always, never
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+  -n, --dry-run              Don't actually write the lockfile
+      --recursive            Force updating all dependencies of [SPEC]... as well
+      --precise <PRECISE>    Update [SPEC] to exactly PRECISE
+  -q, --quiet                Do not print cargo log messages
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Package Selection:
   -w, --workspace  Only update the workspace packages
diff --git a/tests/testsuite/cargo_vendor/help/stdout.log b/tests/testsuite/cargo_vendor/help/stdout.log
index 7f37ab56edd..36a2fdf5b9c 100644
--- a/tests/testsuite/cargo_vendor/help/stdout.log
+++ b/tests/testsuite/cargo_vendor/help/stdout.log
@@ -13,6 +13,7 @@ Options:
   -q, --quiet                  Do not print cargo log messages
   -v, --verbose...             Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>           Coloring: auto, always, never
+      --warnings <warnings>    Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>     Override a configuration value
   -Z <FLAG>                    Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for
                                details
diff --git a/tests/testsuite/cargo_verify_project/help/stdout.log b/tests/testsuite/cargo_verify_project/help/stdout.log
index a61534500d5..c61c042d4c3 100644
--- a/tests/testsuite/cargo_verify_project/help/stdout.log
+++ b/tests/testsuite/cargo_verify_project/help/stdout.log
@@ -3,12 +3,13 @@ Check correctness of crate manifest
 Usage: cargo[EXE] verify-project [OPTIONS]
 
 Options:
-  -q, --quiet               Do not print cargo log messages
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-      --color <WHEN>        Coloring: auto, always, never
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+  -q, --quiet                Do not print cargo log messages
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Manifest Options:
       --manifest-path <PATH>  Path to Cargo.toml
diff --git a/tests/testsuite/cargo_version/help/stdout.log b/tests/testsuite/cargo_version/help/stdout.log
index 3f79051ad40..3a3d0369ea3 100644
--- a/tests/testsuite/cargo_version/help/stdout.log
+++ b/tests/testsuite/cargo_version/help/stdout.log
@@ -3,12 +3,13 @@ Show version information
 Usage: cargo[EXE] version [OPTIONS]
 
 Options:
-  -q, --quiet               Do not print cargo log messages
-  -v, --verbose...          Use verbose output (-vv very verbose/build.rs output)
-      --color <WHEN>        Coloring: auto, always, never
-      --config <KEY=VALUE>  Override a configuration value
-  -Z <FLAG>                 Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
-  -h, --help                Print help
+  -q, --quiet                Do not print cargo log messages
+  -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
+      --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
+      --config <KEY=VALUE>   Override a configuration value
+  -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
+  -h, --help                 Print help
 
 Manifest Options:
       --frozen   Require Cargo.lock and cache are up to date
diff --git a/tests/testsuite/cargo_yank/help/stdout.log b/tests/testsuite/cargo_yank/help/stdout.log
index 61dc800c7e0..27a2b5c99ec 100644
--- a/tests/testsuite/cargo_yank/help/stdout.log
+++ b/tests/testsuite/cargo_yank/help/stdout.log
@@ -14,6 +14,7 @@ Options:
   -q, --quiet                Do not print cargo log messages
   -v, --verbose...           Use verbose output (-vv very verbose/build.rs output)
       --color <WHEN>         Coloring: auto, always, never
+      --warnings <warnings>  Warning behavior [possible values: error, warn, ignore]
       --config <KEY=VALUE>   Override a configuration value
   -Z <FLAG>                  Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details
   -h, --help                 Print help
diff --git a/tests/testsuite/config.rs b/tests/testsuite/config.rs
index 9e77048c3f3..f3901727ca7 100644
--- a/tests/testsuite/config.rs
+++ b/tests/testsuite/config.rs
@@ -107,6 +107,7 @@ impl ConfigBuilder {
             0,
             false,
             None,
+            None,
             false,
             false,
             false,
diff --git a/tests/testsuite/main.rs b/tests/testsuite/main.rs
index d31255d0ae7..9a5a90c8183 100644
--- a/tests/testsuite/main.rs
+++ b/tests/testsuite/main.rs
@@ -175,6 +175,7 @@ mod vendor;
 mod verify_project;
 mod version;
 mod warn_on_failure;
+mod warning_override;
 mod weak_dep_features;
 mod workspaces;
 mod yank;
diff --git a/tests/testsuite/warning_override.rs b/tests/testsuite/warning_override.rs
new file mode 100644
index 00000000000..982240e8741
--- /dev/null
+++ b/tests/testsuite/warning_override.rs
@@ -0,0 +1,85 @@
+//! Tests for overriding warning behavior using `--warnings=` on the CLI or `term.warnings` config option.
+
+use cargo_test_support::{project, Project};
+
+const WARNING1: &'static str = "[WARNING] unused variable: `x`";
+const WARNING2: &'static str = "[WARNING] unused config key `build.xyz` in `[..]`";
+
+fn make_project(main_src: &str) -> Project {
+    project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.0.1"
+                authors = []
+            "#,
+        )
+        .file("src/main.rs", &format!("fn main() {{ {} }}", main_src))
+        .build()
+}
+
+#[cargo_test]
+fn rustc_warnings() {
+    let p = make_project("let x = 3;");
+    p.cargo("check --warnings=warn")
+        .with_stderr_contains(WARNING1)
+        .run();
+
+    p.cargo("check --warnings=error")
+        .with_stderr_contains(WARNING1)
+        .with_stderr_contains(
+            "[ERROR] warnings detected and warnings are disallowed by configuration",
+        )
+        .with_status(101)
+        .run();
+
+    p.cargo("check --warnings=ignore")
+        .with_stderr_does_not_contain(WARNING1)
+        .run();
+}
+
+#[cargo_test]
+fn config() {
+    let p = make_project("let x = 3;");
+    p.cargo("check")
+        .env("CARGO_TERM_WARNINGS", "error")
+        .with_stderr_contains(WARNING1)
+        .with_stderr_contains(
+            "[ERROR] warnings detected and warnings are disallowed by configuration",
+        )
+        .with_status(101)
+        .run();
+
+    // CLI has precedence over config
+    p.cargo("check --warnings=ignore")
+        .env("CARGO_TERM_WARNINGS", "error")
+        .with_stderr_does_not_contain(WARNING1)
+        .run();
+
+    p.cargo("check")
+        .env("CARGO_TERM_WARNINGS", "ignore")
+        .with_stderr_does_not_contain(WARNING1)
+        .run();
+}
+
+#[cargo_test]
+/// Warnings that come from cargo rather than rustc
+fn cargo_warnings() {
+    let p = make_project("");
+    p.change_file(".cargo/config.toml", "[build]\nxyz = false");
+    p.cargo("check").with_stderr_contains(WARNING2).run();
+
+    p.cargo("check --warnings=error")
+        .with_stderr_contains(WARNING2)
+        .with_stderr_contains(
+            "[ERROR] warnings detected and warnings are disallowed by configuration",
+        )
+        .with_status(101)
+        .run();
+
+    p.cargo("check --warnings=ignore")
+        .with_stderr_does_not_contain(WARNING2)
+        .run();
+}