feat: Add build.detect-antivirus config option

To allow disabling the warning.

Author: madsmtm

src/cargo/core/compiler/build_config.rs

@@ -130,8 +130,18 @@ impl BuildConfig {
             _ => Vec::new(),
         };
 
-        // Enabled by default (for now only when the unstable flag is set).
-        let detect_antivirus = gctx.cli_unstable().detect_antivirus;
+        let detect_antivirus = match (cfg.detect_antivirus, gctx.cli_unstable().detect_antivirus) {
+            // Enabled by default (for now only when the flag is set).
+            (None, unstable_flag) => unstable_flag,
+            // But allow overriding with configuration option.
+            (Some(cfg_option), true) => cfg_option,
+            (Some(_), false) => {
+                gctx.shell().warn(
+                    "ignoring 'build.detect-antivirus' config, pass `-Zdetect-antivirus` to enable it",
+                )?;
+                false
+            }
+        };
 
         Ok(BuildConfig {
             requested_kinds,

src/cargo/core/features.rs

@@ -854,7 +854,7 @@ unstable_cli_options!(
     checksum_freshness: bool = ("Use a checksum to determine if output is fresh rather than filesystem mtime"),
     codegen_backend: bool = ("Enable the `codegen-backend` option in profiles in .cargo/config.toml file"),
     config_include: bool = ("Enable the `include` key in config files"),
-    detect_antivirus: bool = ("Enable the experimental antivirus detection"),
+    detect_antivirus: bool = ("Enable the experimental antivirus detection and the config option to disable it"),
     direct_minimal_versions: bool = ("Resolve minimal dependency versions instead of maximum (direct dependencies only)"),
     dual_proc_macros: bool = ("Build proc-macros for both the host and the target"),
     feature_unification: bool = ("Enable new feature unification modes in workspaces"),

src/cargo/util/context/mod.rs

@@ -2770,6 +2770,8 @@ pub struct CargoBuildConfig {
     pub sbom: Option<bool>,
     /// Unstable feature `-Zbuild-analysis`.
     pub analysis: Option<CargoBuildAnalysis>,
+    /// Unstable feature `-Zdetect-antivirus`.
+    pub detect_antivirus: Option<bool>,
 }
 
 /// Metrics collection for build analysis.

src/doc/src/reference/unstable.md

@@ -1954,7 +1954,24 @@ This layout change unblocks work towards caching and locking improvements.
 
 The `-Zdetect-antivirus` flag enables detection of antivirus software that might make launching a binary for the first time slower (which in turn makes Cargo's build scripts and tests slower), and outputs a notice to the user if this is the case.
 
-This feature will be enabled by default in the future.
+This feature will be enabled by default in the future (the flag acts as-if this future is now).
+
+### Reference for `build.detect-antivirus`
+
+* Type: boolean
+* Default: true (when `-Zdetect-antivirus` is enabled)
+* Environment: CARGO_BUILD_DETECT_ANTIVIRUS
+
+Allow opting out of antivirus detection.
+
+```toml
+# Example ~/.cargo/config.toml
+
+# Disable warning, e.g. if using a workplace-issued Mac that
+# doesn't allow granting Developer Tool permissions.
+[build]
+detect-antivirus = false
+```
 
 
 # Stabilized and removed features