fix(install): resolve repo_version placeholder in driver dry-run output

apps/rocm/src/main.rs

@@ -3457,6 +3457,24 @@ fn driver_command(phase: DriverCommandPhase, command: &str) -> DriverPlanCommand
     }
 }
 
+/// Resolve a `${VAR:-default}` shell parameter-expansion template to its
+/// effective value for user-facing display: the value of `VAR` when it is set
+/// and non-empty (matching the shell `:-` semantics), otherwise the default.
+/// Anything that is not a recognized `${VAR:-default}` template is returned
+/// unchanged.
+fn resolve_repo_version(expr: &str) -> String {
+    let Some(inner) = expr.strip_prefix("${").and_then(|s| s.strip_suffix('}')) else {
+        return expr.to_owned();
+    };
+    let Some((var, default)) = inner.split_once(":-") else {
+        return expr.to_owned();
+    };
+    std::env::var(var)
+        .ok()
+        .filter(|value| !value.is_empty())
+        .unwrap_or_else(|| default.to_owned())
+}
+
 fn render_driver_install_plan(plan: &DriverInstallPlan, yes: bool, dry_run: bool) -> String {
     let mut output = String::new();
     let _ = writeln!(output, "driver install plan");
@@ -3476,7 +3494,11 @@ fn render_driver_install_plan(plan: &DriverInstallPlan, yes: bool, dry_run: bool
         empty_as_unknown(&plan.version_id)
     );
     let _ = writeln!(output, "  codename: {}", empty_as_unknown(&plan.codename));
-    let _ = writeln!(output, "  repo_version: {}", plan.repo_version_expr);
+    let _ = writeln!(
+        output,
+        "  repo_version: {}",
+        resolve_repo_version(&plan.repo_version_expr)
+    );
     let _ = writeln!(output, "  reason: {}", plan.reason);
     if !plan.preflight_checks.is_empty() {
         let _ = writeln!(output, "  preflight_checks:");
@@ -24004,6 +24026,65 @@ VERSION_CODENAME=noble
         assert!(rendered.contains("add --dkms"));
     }
 
+    #[test]
+    fn resolve_repo_version_uses_default_when_env_unset() {
+        // A made-up variable name that nothing else sets keeps this race-free.
+        assert_eq!(
+            resolve_repo_version("${ROCM_CLI_TEST_UNSET_REPO_VERSION:-7.2.4}"),
+            "7.2.4"
+        );
+    }
+
+    #[test]
+    #[allow(unsafe_code)] // std::env::set_var/remove_var are unsafe in edition 2024
+    fn resolve_repo_version_prefers_env_value_when_set() {
+        // Uses a unique per-test variable name so it cannot race with other
+        // tests reading the real ROCM_CLI_AMDGPU_VERSION variable.
+        let var = "ROCM_CLI_TEST_REPO_VERSION_OVERRIDE";
+        unsafe {
+            std::env::set_var(var, "9.9.9");
+        }
+        let resolved = resolve_repo_version(&format!("${{{var}:-7.2.4}}"));
+        unsafe {
+            std::env::remove_var(var);
+        }
+        assert_eq!(resolved, "9.9.9");
+    }
+
+    #[test]
+    #[allow(unsafe_code)] // std::env::set_var/remove_var are unsafe in edition 2024
+    fn resolve_repo_version_treats_empty_env_as_unset() {
+        let var = "ROCM_CLI_TEST_REPO_VERSION_EMPTY";
+        unsafe {
+            std::env::set_var(var, "");
+        }
+        let resolved = resolve_repo_version(&format!("${{{var}:-7.2.4}}"));
+        unsafe {
+            std::env::remove_var(var);
+        }
+        assert_eq!(resolved, "7.2.4");
+    }
+
+    #[test]
+    fn resolve_repo_version_passes_through_non_template() {
+        assert_eq!(resolve_repo_version("7.2.4"), "7.2.4");
+    }
+
+    #[test]
+    fn driver_plan_dry_run_repo_version_line_is_resolved() {
+        // Regression for the dry-run output leaking the raw shell placeholder on
+        // the `repo_version:` line instead of the effective version.
+        let os_release = r#"
+ID=rhel
+VERSION_ID="9.7"
+"#;
+        let plan = build_driver_install_plan(&test_examine("linux", false), os_release, true);
+        let rendered = render_driver_install_plan(&plan, false, true);
+
+        assert!(rendered.contains("repo_version: 7.2.4"));
+        assert!(!rendered.contains("repo_version: ${ROCM_CLI_AMDGPU_VERSION:-7.2.4}"));
+    }
+
     #[test]
     fn driver_plan_debian_12_omits_linux_modules_extra() {
         let os_release = r#"