feat: add cleanup option for auto-installed dependencies in build command

- Introduced a new `cleanup_deps` flag in the build command to remove dependencies that were automatically installed during the build process.
- Implemented an `InterruptWatcher` to handle Ctrl-C interruptions gracefully during the build process.
- Enhanced the `AutoInstalledDependencyTracker` to track and manage auto-installed dependencies, allowing for cleanup after the build.
- Updated the CLI to parse the new `cleanup_deps` flag and integrated it into the build workflow.
- Added tests to ensure the correct parsing of the `cleanup_deps` flag and the functionality of the dependency tracking and cleanup process.
- Improved logging for package removal operations to include a verbose mode controlled by the `DEPOT_VERBOSE_REMOVE` environment variable.

.gitlab-ci.yml

@@ -14,16 +14,3 @@ sast:
 
 secret_detection:
   stage: secret-detection
-
-rust_test:
-  stage: test
-  image: rust:1.93.1
-  cache:
-    key: cargo
-    paths:
-      - .cargo/
-      - target/
-  variables:
-    CARGO_HOME: "$CI_PROJECT_DIR/.cargo"
-  script:
-    - cargo test --workspace --all-features --locked

Cargo.lock

@@ -380,7 +380,7 @@ dependencies = [
  "mio",
  "parking_lot",
  "rustix",
- "signal-hook",
+ "signal-hook 0.3.18",
  "signal-hook-mio",
  "winapi",
 ]
@@ -445,6 +445,7 @@ dependencies = [
  "serde",
  "serde_ignored",
  "sha2",
+ "signal-hook 0.4.3",
  "suppaftp",
  "sys-mount",
  "tar",
@@ -1962,6 +1963,16 @@ dependencies = [
  "signal-hook-registry",
 ]
 
+[[package]]
+name = "signal-hook"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3b57709da74f9ff9f4a27dce9526eec25ca8407c45a7887243b031a58935fb8e"
+dependencies = [
+ "libc",
+ "signal-hook-registry",
+]
+
 [[package]]
 name = "signal-hook-mio"
 version = "0.2.5"
@@ -1970,7 +1981,7 @@ checksum = "b75a19a7a740b25bc7944bdee6172368f988763b744e3d4dfe753f6b4ece40cc"
 dependencies = [
  "libc",
  "mio",
- "signal-hook",
+ "signal-hook 0.3.18",
 ]
 
 [[package]]

Cargo.toml

@@ -45,6 +45,7 @@ b2sum-rust = "0.3.0"
 serde_ignored = "0.1.14"
 lz4_flex = "0.12.0"
 lzma-rust2 = "0.16.2"
+signal-hook = "0.4.3"
 
 [dev-dependencies]
 tempfile = "=3.27.0"

README.md

@@ -48,6 +48,7 @@ depot install zlib-1.2.11-1-x86_64.depot.pkg.tar.zst
 - `remove <PACKAGE>`: Remove an installed package.
 - `build <SPEC>`: Build a package and create an archive without installing.
   - Use `--install-deps` to automatically install missing build/runtime/test dependencies before fetching/building.
+  - Use `--cleanup-deps` to remove dependencies auto-installed for the build after the command finishes; when combined with `--install`, runtime dependencies are kept.
   - Missing test dependencies automatically disable test execution unless `--test-deps` or `[install].test_deps = true` is set.
 - `update [PACKAGE ...]`: Update installed packages from configured repositories.
   - With no package names, updates every installed package that has a newer repo version available.

src/builder/mod.rs

@@ -111,10 +111,33 @@ fn apply_replacement_rules(current: &mut [String], replacements: &[String], labe
     }
 }
 
+fn sanitize_flag_list(values: Vec<String>, label: &str) -> Vec<String> {
+    let mut sanitized = Vec::with_capacity(values.len());
+    for value in values {
+        let trimmed = value.trim();
+        if trimmed.is_empty() {
+            continue;
+        }
+        if trimmed == "-" {
+            crate::log_warn!(
+                "Dropping invalid {} entry '-'; compiler/linker flag lists cannot contain a bare dash",
+                label
+            );
+            continue;
+        }
+        sanitized.push(trimmed.to_string());
+    }
+    sanitized
+}
+
 fn replaced_flags(values: &[String], replacements: &[String], label: &str) -> Vec<String> {
     let mut current = values.to_vec();
-    apply_replacement_rules(&mut current, replacements, label);
-    current
+    apply_replacement_rules(
+        &mut current,
+        replacements,
+        &format!("{label} replacement rules"),
+    );
+    sanitize_flag_list(current, label)
 }
 
 pub(crate) fn install_dirs(flags: &crate::package::BuildFlags) -> InstallDirs {
@@ -145,25 +168,21 @@ pub(crate) fn install_dirs(flags: &crate::package::BuildFlags) -> InstallDirs {
 fn compiler_flag_sets(
     flags: &crate::package::BuildFlags,
 ) -> (Vec<String>, Vec<String>, Vec<String>, Vec<String>) {
-    let mut cflags = replaced_flags(
-        &flags.cflags,
-        &flags.replace_cflags,
-        "build.flags.replace_cflags",
-    );
+    let mut cflags = replaced_flags(&flags.cflags, &flags.replace_cflags, "build.flags.cflags");
     let mut cxxflags = replaced_flags(
         &flags.cxxflags,
         &flags.replace_cxxflags,
-        "build.flags.replace_cxxflags",
+        "build.flags.cxxflags",
     );
     let mut ldflags = replaced_flags(
         &flags.ldflags,
         &flags.replace_ldflags,
-        "build.flags.replace_ldflags",
+        "build.flags.ldflags",
     );
     let ltoflags = replaced_flags(
         &flags.ltoflags,
         &flags.replace_ltoflags,
-        "build.flags.replace_ltoflags",
+        "build.flags.ltoflags",
     );
 
     if flags.use_lto && !ltoflags.is_empty() {
@@ -179,7 +198,7 @@ pub(crate) fn effective_rustflags(flags: &crate::package::BuildFlags) -> Vec<Str
     replaced_flags(
         &flags.rustflags,
         &flags.replace_rustflags,
-        "build.flags.replace_rustflags",
+        "build.flags.rustflags",
     )
 }
 
@@ -663,6 +682,36 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_standard_build_env_drops_bare_dash_flags() {
+        let mut spec = mk_spec(vec!["-O2", "-", ""], vec!["-Wl,--as-needed", "  "]);
+        spec.build.flags.cxxflags = vec!["-O2".into(), "-".into(), "-fno-exceptions".into()];
+        spec.build.flags.ltoflags = vec!["-".into(), "-flto=thin".into()];
+        spec.build.flags.use_lto = true;
+
+        let env = standard_build_env(&spec, None, true, true);
+        assert!(
+            env.iter()
+                .any(|(k, v)| k == "CFLAGS" && v == "-O2 -flto=thin"),
+            "expected bare dash entries to be removed from CFLAGS"
+        );
+        assert!(
+            env.iter()
+                .any(|(k, v)| k == "CXXFLAGS" && v == "-O2 -fno-exceptions -flto=thin"),
+            "expected bare dash entries to be removed from CXXFLAGS"
+        );
+        assert!(
+            env.iter()
+                .any(|(k, v)| k == "LDFLAGS" && v == "-Wl,--as-needed -flto=thin"),
+            "expected blank and bare dash entries to be removed from LDFLAGS"
+        );
+        assert!(
+            env.iter()
+                .any(|(k, v)| k == "LTOFLAGS" && v == "-flto=thin"),
+            "expected bare dash entries to be removed from LTOFLAGS"
+        );
+    }
+
     #[test]
     fn test_standard_build_env_skips_lto_injection_when_disabled() {
         let mut spec = mk_spec(vec!["-O2"], vec!["-Wl,--as-needed"]);

src/cli.rs

@@ -97,6 +97,10 @@ pub enum Commands {
         /// Automatically install missing dependencies before building
         #[arg(long)]
         install_deps: bool,
+
+        /// Remove dependencies auto-installed for this build after the command finishes
+        #[arg(long)]
+        cleanup_deps: bool,
     },
     /// Update installed packages from configured repositories
     Update {
@@ -360,4 +364,13 @@ mod tests {
             _ => panic!("expected build command"),
         }
     }
+
+    #[test]
+    fn build_cleanup_deps_flag_is_parsed() {
+        let cli = Cli::try_parse_from(["depot", "build", "--cleanup-deps", "pkg.toml"]).unwrap();
+        match cli.command {
+            Commands::Build { cleanup_deps, .. } => assert!(cleanup_deps),
+            _ => panic!("expected build command"),
+        }
+    }
 }

src/commands.rs

@@ -6,11 +6,14 @@ use crate::{
 use anyhow::{Context, Result};
 use git2::Direction;
 use indicatif::{ProgressBar, ProgressDrawTarget, ProgressStyle};
+use signal_hook::consts::SIGINT;
 use std::cmp::Ordering;
 use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
 use std::fs;
 use std::io::IsTerminal;
 use std::path::{Path, PathBuf};
+use std::sync::Arc;
+use std::sync::atomic::{AtomicBool, Ordering as AtomicOrdering};
 use url::Url;
 use walkdir::WalkDir;
 
@@ -42,22 +45,28 @@ fn should_delegate_live_rootfs_installs(rootfs: &Path) -> bool {
 
 const DEPOT_INSTALL_CONTEXT_ENV: &str = "DEPOT_INSTALL_CONTEXT";
 const INSTALL_CONTEXT_UPDATE: &str = "update";
+const INSTALL_CONTEXT_PLANNED: &str = "planned";
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 enum InstallInvocationContext {
     Default,
     Update,
+    Planned,
 }
 
 fn current_install_invocation_context() -> InstallInvocationContext {
     match std::env::var(DEPOT_INSTALL_CONTEXT_ENV).as_deref() {
         Ok(INSTALL_CONTEXT_UPDATE) => InstallInvocationContext::Update,
+        Ok(INSTALL_CONTEXT_PLANNED) => InstallInvocationContext::Planned,
         _ => InstallInvocationContext::Default,
     }
 }
 
 fn suppress_nested_install_output() -> bool {
-    current_install_invocation_context() == InstallInvocationContext::Update
+    matches!(
+        current_install_invocation_context(),
+        InstallInvocationContext::Update | InstallInvocationContext::Planned
+    )
 }
 
 fn install_test_deps_enabled(cli_test_deps: bool, config: &config::Config) -> bool {
@@ -220,12 +229,183 @@ fn run_child_install_command(
             clean: options.clean,
             lib32_only: false,
             install_test_deps: options.install_test_deps,
-            install_context: None,
+            install_context: Some(INSTALL_CONTEXT_PLANNED),
             dep_chain: None,
         },
     )
 }
 
+#[derive(Clone)]
+struct InterruptWatcher {
+    interrupted: Arc<AtomicBool>,
+}
+
+impl InterruptWatcher {
+    fn install() -> Result<Self> {
+        let interrupted = Arc::new(AtomicBool::new(false));
+        signal_hook::flag::register(SIGINT, interrupted.clone())
+            .context("Failed to register Ctrl-C handler")?;
+        Ok(Self { interrupted })
+    }
+
+    fn was_interrupted(&self) -> bool {
+        self.interrupted.load(AtomicOrdering::Relaxed)
+    }
+
+    fn check(&self) -> Result<()> {
+        if self.was_interrupted() {
+            anyhow::bail!("Interrupted by Ctrl-C");
+        }
+        Ok(())
+    }
+}
+
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+enum AutoInstalledDependencyKind {
+    Build,
+    Runtime,
+    Test,
+}
+
+#[derive(Debug, Default, Clone)]
+struct AutoInstalledDependencyTracker {
+    install_order: Vec<String>,
+    build: BTreeSet<String>,
+    runtime: BTreeSet<String>,
+    test: BTreeSet<String>,
+}
+
+impl AutoInstalledDependencyTracker {
+    fn record_plan(
+        &mut self,
+        plan: &planner::ExecutionPlan,
+        requested_deps: &[String],
+        kind: AutoInstalledDependencyKind,
+    ) {
+        if requested_deps.is_empty() {
+            return;
+        }
+
+        for step in plan.actionable_steps() {
+            if !self.install_order.contains(&step.package) {
+                self.install_order.push(step.package.clone());
+            }
+        }
+
+        let closure = plan_dependency_closure_for_requested_deps(plan, requested_deps);
+        let target = match kind {
+            AutoInstalledDependencyKind::Build => &mut self.build,
+            AutoInstalledDependencyKind::Runtime => &mut self.runtime,
+            AutoInstalledDependencyKind::Test => &mut self.test,
+        };
+        target.extend(closure);
+    }
+
+    fn cleanup_targets(&self, include_runtime: bool) -> Vec<String> {
+        let mut remove = self.build.clone();
+        remove.extend(self.test.iter().cloned());
+        if include_runtime {
+            remove.extend(self.runtime.iter().cloned());
+        } else {
+            remove.retain(|package| !self.runtime.contains(package));
+        }
+
+        self.install_order
+            .iter()
+            .rev()
+            .filter(|package| remove.contains(*package))
+            .cloned()
+            .collect()
+    }
+
+    fn is_empty(&self) -> bool {
+        self.build.is_empty() && self.runtime.is_empty() && self.test.is_empty()
+    }
+}
+
+fn plan_dependency_closure_for_requested_deps(
+    plan: &planner::ExecutionPlan,
+    requested_deps: &[String],
+) -> HashSet<String> {
+    let requested: HashSet<_> = requested_deps.iter().map(String::as_str).collect();
+    let mut roots = Vec::new();
+    let mut children_by_parent: HashMap<String, Vec<String>> = HashMap::new();
+
+    for step in plan.actionable_steps() {
+        if step.requested_by.iter().any(|reason| {
+            reason
+                .strip_prefix("dependency ")
+                .is_some_and(|dep| requested.contains(dep))
+        }) {
+            roots.push(step.package.clone());
+        }
+
+        for reason in &step.requested_by {
+            if let Some((parent, _dep)) = reason.split_once(" needs ") {
+                let children = children_by_parent.entry(parent.to_string()).or_default();
+                if !children.contains(&step.package) {
+                    children.push(step.package.clone());
+                }
+            }
+        }
+    }
+
+    let mut stack = roots;
+    let mut closure = HashSet::new();
+    while let Some(package) = stack.pop() {
+        if !closure.insert(package.clone()) {
+            continue;
+        }
+        if let Some(children) = children_by_parent.get(&package) {
+            stack.extend(children.iter().cloned());
+        }
+    }
+
+    closure
+}
+
+fn prompt_for_dependency_cleanup(packages: &[String]) -> Result<bool> {
+    let assume_yes = ui::assume_yes_enabled();
+    ui::set_assume_yes(false);
+    let result = ui::prompt_package_action("dependency cleanup", packages, true);
+    ui::set_assume_yes(assume_yes);
+    result
+}
+
+fn cleanup_auto_installed_dependencies(
+    tracker: &AutoInstalledDependencyTracker,
+    rootfs: &Path,
+    config: &config::Config,
+    include_runtime: bool,
+    prompt: bool,
+) -> Result<()> {
+    let db_path = config.installed_db_path(rootfs);
+    let installed = db::get_installed_packages(&db_path)?;
+    let targets: Vec<String> = tracker
+        .cleanup_targets(include_runtime)
+        .into_iter()
+        .filter(|package| installed.contains(package))
+        .collect();
+
+    if targets.is_empty() {
+        return Ok(());
+    }
+
+    if prompt && !prompt_for_dependency_cleanup(&targets)? {
+        return Ok(());
+    }
+
+    ui::info(format!(
+        "Removing auto-installed dependencies: {}",
+        targets.join(", ")
+    ));
+    for package in targets {
+        remove_installed_package_with_hooks(&package, rootfs, config)?;
+    }
+
+    Ok(())
+}
+
 fn parse_licenses_from_toml(metadata: &toml::Value) -> Vec<String> {
     if let Some(s) = metadata.get("license").and_then(|v| v.as_str()) {
         return vec![s.to_string()];
@@ -3180,7 +3360,7 @@ fn execute_install_plan_with_child_commands(
                     clean: options.clean,
                     lib32_only: batch.lib32_only,
                     install_test_deps: options.install_test_deps,
-                    install_context: None,
+                    install_context: Some(INSTALL_CONTEXT_PLANNED),
                     dep_chain: None,
                 },
             )?;
@@ -3977,6 +4157,7 @@ pub fn run(cli: Cli) -> Result<()> {
             spec,
             install,
             install_deps,
+            cleanup_deps,
         } => {
             warn_if_running_as_root_for_build("build", &cli.rootfs);
             let spec_path = spec.or(spec_pos).context("No spec file provided")?;
@@ -3985,7 +4166,13 @@ pub fn run(cli: Cli) -> Result<()> {
 
             let config = config::Config::for_rootfs(&cli.rootfs);
             let install_test_deps = install_test_deps_enabled(cli_test_deps, &config);
-
+            let interrupt_watcher = if cleanup_deps {
+                Some(InterruptWatcher::install()?)
+            } else {
+                None
+            };
+            let mut auto_installed_deps = AutoInstalledDependencyTracker::default();
+            let build_result: Result<()> = (|| {
                 // Apply system overrides
                 pkg_spec.apply_config(&config);
                 let requested_outputs = requested_outputs(&pkg_spec, cli.lib32_only);
@@ -4024,16 +4211,24 @@ pub fn run(cli: Cli) -> Result<()> {
                 } else if cli.no_deps
                     || !should_install_test_deps(&pkg_spec, install_test_deps, requested_outputs)
                 {
-                maybe_disable_tests_for_missing_deps(&mut pkg_spec, &db_path, requested_outputs)?;
+                    maybe_disable_tests_for_missing_deps(
+                        &mut pkg_spec,
+                        &db_path,
+                        requested_outputs,
+                    )?;
                 }
 
-            // Check build dependencies
                 if !cli.no_deps {
                     deps::print_dep_status_for_outputs(&pkg_spec, &db_path, requested_outputs)?;
-                let missing_required = merge_missing_dependencies(
-                    deps::check_build_deps_for_outputs(&pkg_spec, &db_path, requested_outputs)?,
-                    deps::check_runtime_deps_for_outputs(&pkg_spec, &db_path, requested_outputs)?,
-                );
+                    let missing_build =
+                        deps::check_build_deps_for_outputs(&pkg_spec, &db_path, requested_outputs)?;
+                    let missing_runtime = deps::check_runtime_deps_for_outputs(
+                        &pkg_spec,
+                        &db_path,
+                        requested_outputs,
+                    )?;
+                    let missing_required =
+                        merge_missing_dependencies(missing_build.clone(), missing_runtime.clone());
                     if !missing_required.is_empty() {
                         ui::warn(format!(
                             "Missing dependencies: {}",
@@ -4055,6 +4250,18 @@ pub fn run(cli: Cli) -> Result<()> {
                                 lib32_only_requested_specs: false,
                             },
                         )?;
+                        if cleanup_deps {
+                            auto_installed_deps.record_plan(
+                                &dep_plan,
+                                &missing_build,
+                                AutoInstalledDependencyKind::Build,
+                            );
+                            auto_installed_deps.record_plan(
+                                &dep_plan,
+                                &missing_runtime,
+                                AutoInstalledDependencyKind::Runtime,
+                            );
+                        }
                         print_plan_summary(&dep_plan);
                         if !install_deps {
                             if cli.dry_run {
@@ -4069,7 +4276,9 @@ pub fn run(cli: Cli) -> Result<()> {
                             );
                         }
                         if cli.dry_run {
-                        ui::info("Dry run enabled, stopping before dependency installation/build.");
+                            ui::info(
+                                "Dry run enabled, stopping before dependency installation/build.",
+                            );
                             return Ok(());
                         }
                         execute_install_plan_with_child_commands(
@@ -4090,8 +4299,11 @@ pub fn run(cli: Cli) -> Result<()> {
                     deps::require_build_deps_for_outputs(&pkg_spec, &db_path, requested_outputs)?;
                     deps::require_runtime_deps_for_outputs(&pkg_spec, &db_path, requested_outputs)?;
                     if should_install_test_deps(&pkg_spec, install_test_deps, requested_outputs) {
-                    let missing_test =
-                        deps::check_test_deps_for_outputs(&pkg_spec, &db_path, requested_outputs)?;
+                        let missing_test = deps::check_test_deps_for_outputs(
+                            &pkg_spec,
+                            &db_path,
+                            requested_outputs,
+                        )?;
                         if !missing_test.is_empty() {
                             let local_sibling_root = spec_path
                                 .parent()
@@ -4122,6 +4334,14 @@ pub fn run(cli: Cli) -> Result<()> {
                                 Err(err) => return Err(err),
                             };
 
+                            if cleanup_deps && !pkg_spec.build.flags.skip_tests {
+                                auto_installed_deps.record_plan(
+                                    &dep_plan,
+                                    &missing_test,
+                                    AutoInstalledDependencyKind::Test,
+                                );
+                            }
+
                             if !pkg_spec.build.flags.skip_tests && !dep_plan.steps.is_empty() {
                                 ui::warn(format!(
                                     "Missing test dependencies: {}",
@@ -4163,8 +4383,11 @@ pub fn run(cli: Cli) -> Result<()> {
                                 }
                             }
 
-                        if should_install_test_deps(&pkg_spec, install_test_deps, requested_outputs)
-                        {
+                            if should_install_test_deps(
+                                &pkg_spec,
+                                install_test_deps,
+                                requested_outputs,
+                            ) {
                                 let missing_test = deps::check_test_deps_for_outputs(
                                     &pkg_spec,
                                     &db_path,
@@ -4193,21 +4416,27 @@ pub fn run(cli: Cli) -> Result<()> {
 
                 let mut build_lock = locking::open_lock(&config)?;
                 let build_lock_path = locking::lock_path(&config);
-            let _build_lock_guard = locking::try_write(&mut build_lock, &build_lock_path, "build")?;
+                let _build_lock_guard =
+                    locking::try_write(&mut build_lock, &build_lock_path, "build")?;
 
                 if cli.dry_run {
                     ui::info("Dry run enabled, stopping before fetch/build.");
                     return Ok(());
                 }
 
-            // TODO(snapper): create pre-build snapshot before fetch/build starts.
+                if let Some(watcher) = interrupt_watcher.as_ref() {
+                    watcher.check()?;
+                }
+
                 let src_dir = source::prepare(&pkg_spec, &config.cache_dir, &config.build_dir)?;
+                if let Some(watcher) = interrupt_watcher.as_ref() {
+                    watcher.check()?;
+                }
 
                 let destdir = config
                     .build_dir
                     .join("destdir")
                     .join(&pkg_spec.package.name);
-            // Build with optional cross-compilation
                 let cross_config = cli
                     .cross_prefix
                     .as_ref()
@@ -4221,15 +4450,20 @@ pub fn run(cli: Cli) -> Result<()> {
                         cross_config.as_ref(),
                         !cli.no_flags,
                     )?;
+                    if let Some(watcher) = interrupt_watcher.as_ref() {
+                        watcher.check()?;
+                    }
                 }
 
                 if !cli.lib32_only {
                     staging::add_licenses(&src_dir, &destdir, &pkg_spec.package.name)?;
                     install::scripts::stage_scripts_from_spec_dir(&pkg_spec, &destdir)?;
                     staging::process(&destdir, &pkg_spec)?;
+                    if let Some(watcher) = interrupt_watcher.as_ref() {
+                        watcher.check()?;
+                    }
                 }
 
-            // Create package archive(s) — support multiple outputs from a single spec.
                 let arch = cli
                     .cross_prefix
                     .as_deref()
@@ -4258,6 +4492,9 @@ pub fn run(cli: Cli) -> Result<()> {
                             ));
                         }
                         created_files.push(pkg_file);
+                        if let Some(watcher) = interrupt_watcher.as_ref() {
+                            watcher.check()?;
+                        }
                     }
                 }
 
@@ -4286,12 +4523,14 @@ pub fn run(cli: Cli) -> Result<()> {
                     }
                     created_files.push(pkg_file);
                     lib32_install_bundle = Some((lib32_spec, lib32_destdir));
+                    if let Some(watcher) = interrupt_watcher.as_ref() {
+                        watcher.check()?;
+                    }
                 }
 
                 for f in &created_files {
                     ui::success(format!("Build complete. Package created: {}", f.display()));
                 }
-            // TODO(snapper): create post-build snapshot after package build completes.
 
                 if install {
                     let mut install_targets = Vec::new();
@@ -4311,6 +4550,9 @@ pub fn run(cli: Cli) -> Result<()> {
                         ));
                     }
                     if ui::prompt_package_action("installation", &install_targets, false)? {
+                        if let Some(watcher) = interrupt_watcher.as_ref() {
+                            watcher.check()?;
+                        }
                         if should_delegate_live_rootfs_installs(&cli.rootfs) {
                             run_child_install_command(
                                 &created_files,
@@ -4325,9 +4567,6 @@ pub fn run(cli: Cli) -> Result<()> {
                                     install_test_deps,
                                 },
                             )?;
-                        if cli.clean {
-                            clean_build_workspace(&config)?;
-                        }
                             return Ok(());
                         }
 
@@ -4342,8 +4581,12 @@ pub fn run(cli: Cli) -> Result<()> {
                             transaction_plans.extend(output_plans);
                         }
                         if let Some((lib32_spec, lib32_destdir)) = &lib32_install_bundle {
-                        let staged =
-                            plan_staged_install(lib32_spec, lib32_destdir, &cli.rootfs, &config)?;
+                            let staged = plan_staged_install(
+                                lib32_spec,
+                                lib32_destdir,
+                                &cli.rootfs,
+                                &config,
+                            )?;
                             transaction_plans.push(PlannedPackageInstall {
                                 spec: lib32_spec.clone(),
                                 destdir: lib32_destdir.clone(),
@@ -4363,7 +4606,6 @@ pub fn run(cli: Cli) -> Result<()> {
                         )?;
                         for pkg in installed {
                             log_install_success(&pkg);
-                        // TODO(snapper): create post-install snapshot after --install commit succeeds.
                         }
                         run_transaction_hooks_for_plans(
                             &cli.rootfs,
@@ -4393,10 +4635,52 @@ pub fn run(cli: Cli) -> Result<()> {
                     }
                 }
 
+                Ok(())
+            })();
+
+            let interrupted = interrupt_watcher
+                .as_ref()
+                .is_some_and(InterruptWatcher::was_interrupted);
+            match build_result {
+                Ok(()) => {
+                    if cleanup_deps && !auto_installed_deps.is_empty() {
+                        cleanup_auto_installed_dependencies(
+                            &auto_installed_deps,
+                            &cli.rootfs,
+                            &config,
+                            !install,
+                            false,
+                        )?;
+                    }
                     if cli.clean {
                         clean_build_workspace(&config)?;
                     }
                 }
+                Err(err) => {
+                    if cleanup_deps && !auto_installed_deps.is_empty() {
+                        if interrupted {
+                            ui::warn("Build interrupted by Ctrl-C.");
+                        }
+                        if let Err(clean_err) = cleanup_auto_installed_dependencies(
+                            &auto_installed_deps,
+                            &cli.rootfs,
+                            &config,
+                            !install,
+                            interrupted,
+                        ) {
+                            ui::warn(format!(
+                                "Failed to remove auto-installed dependencies: {}",
+                                clean_err
+                            ));
+                        }
+                    }
+                    if interrupted {
+                        anyhow::bail!("Build interrupted by Ctrl-C");
+                    }
+                    return Err(err);
+                }
+            }
+        }
         Commands::Update { packages } => {
             if cli.lib32_only {
                 anyhow::bail!("--lib32-only is not supported with 'update'");
@@ -4917,6 +5201,7 @@ pub fn run(cli: Cli) -> Result<()> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::test_support::TestEnv;
     use std::sync::Mutex;
 
     static ASSUME_YES_TEST_LOCK: Mutex<()> = Mutex::new(());
@@ -6034,6 +6319,126 @@ optional = []
         Ok(())
     }
 
+    #[test]
+    fn suppress_nested_install_output_for_planned_context() {
+        let mut env = TestEnv::new();
+        env.set_var(DEPOT_INSTALL_CONTEXT_ENV, INSTALL_CONTEXT_PLANNED);
+
+        assert!(suppress_nested_install_output());
+        assert_eq!(
+            current_install_invocation_context(),
+            InstallInvocationContext::Planned
+        );
+    }
+
+    #[test]
+    fn plan_dependency_closure_tracks_requested_dependency_roots() {
+        let plan = planner::ExecutionPlan {
+            steps: vec![
+                planner::PlannedStep {
+                    package: "zlib".into(),
+                    action: planner::PlanAction::InstallBinary,
+                    origin: planner::PlanOrigin::Source {
+                        path: PathBuf::from("packages/core/zlib/zlib.toml"),
+                        local_sibling: false,
+                    },
+                    requested_by: vec!["cmake needs zlib".into()],
+                },
+                planner::PlannedStep {
+                    package: "cmake".into(),
+                    action: planner::PlanAction::InstallBinary,
+                    origin: planner::PlanOrigin::Source {
+                        path: PathBuf::from("packages/core/cmake/cmake.toml"),
+                        local_sibling: false,
+                    },
+                    requested_by: vec!["dependency cmake".into()],
+                },
+                planner::PlannedStep {
+                    package: "libffi".into(),
+                    action: planner::PlanAction::InstallBinary,
+                    origin: planner::PlanOrigin::Source {
+                        path: PathBuf::from("packages/core/libffi/libffi.toml"),
+                        local_sibling: false,
+                    },
+                    requested_by: vec!["python needs libffi".into()],
+                },
+                planner::PlannedStep {
+                    package: "python".into(),
+                    action: planner::PlanAction::InstallBinary,
+                    origin: planner::PlanOrigin::Source {
+                        path: PathBuf::from("packages/core/python/python.toml"),
+                        local_sibling: false,
+                    },
+                    requested_by: vec!["dependency python".into()],
+                },
+            ],
+        };
+
+        let cmake_closure = plan_dependency_closure_for_requested_deps(&plan, &["cmake".into()]);
+        assert_eq!(
+            cmake_closure,
+            HashSet::from(["cmake".to_string(), "zlib".to_string()])
+        );
+
+        let python_closure = plan_dependency_closure_for_requested_deps(&plan, &["python".into()]);
+        assert_eq!(
+            python_closure,
+            HashSet::from(["python".to_string(), "libffi".to_string()])
+        );
+    }
+
+    #[test]
+    fn cleanup_targets_keep_runtime_dependencies_for_build_install() {
+        let plan = planner::ExecutionPlan {
+            steps: vec![
+                planner::PlannedStep {
+                    package: "zlib".into(),
+                    action: planner::PlanAction::InstallBinary,
+                    origin: planner::PlanOrigin::Source {
+                        path: PathBuf::from("packages/core/zlib/zlib.toml"),
+                        local_sibling: false,
+                    },
+                    requested_by: vec!["cmake needs zlib".into(), "llvm-runtime needs zlib".into()],
+                },
+                planner::PlannedStep {
+                    package: "cmake".into(),
+                    action: planner::PlanAction::InstallBinary,
+                    origin: planner::PlanOrigin::Source {
+                        path: PathBuf::from("packages/core/cmake/cmake.toml"),
+                        local_sibling: false,
+                    },
+                    requested_by: vec!["dependency cmake".into()],
+                },
+                planner::PlannedStep {
+                    package: "llvm-runtime".into(),
+                    action: planner::PlanAction::InstallBinary,
+                    origin: planner::PlanOrigin::Source {
+                        path: PathBuf::from("packages/core/llvm-runtime/llvm-runtime.toml"),
+                        local_sibling: false,
+                    },
+                    requested_by: vec!["dependency llvm-runtime".into()],
+                },
+            ],
+        };
+        let mut tracker = AutoInstalledDependencyTracker::default();
+        tracker.record_plan(&plan, &["cmake".into()], AutoInstalledDependencyKind::Build);
+        tracker.record_plan(
+            &plan,
+            &["llvm-runtime".into()],
+            AutoInstalledDependencyKind::Runtime,
+        );
+
+        assert_eq!(tracker.cleanup_targets(false), vec!["cmake".to_string()]);
+        assert_eq!(
+            tracker.cleanup_targets(true),
+            vec![
+                "llvm-runtime".to_string(),
+                "cmake".to_string(),
+                "zlib".to_string()
+            ]
+        );
+    }
+
     #[test]
     fn install_success_action_uses_updated_for_replacements() {
         assert_eq!(install_success_action(false), "installed");
@@ -6125,6 +6530,7 @@ optional = []
             spec: None,
             install: false,
             install_deps: false,
+            cleanup_deps: false,
         }));
         assert!(!command_requires_live_root(&Commands::Search {
             query: "foo".to_string(),
@@ -6335,6 +6741,7 @@ optional = []
                 spec: None,
                 install: false,
                 install_deps: false,
+                cleanup_deps: false,
             },
         });
         ui::set_assume_yes(false);

src/db/mod.rs

@@ -14,6 +14,10 @@ fn format_licenses(licenses: &[String]) -> String {
     licenses.join(", ")
 }
 
+fn verbose_remove_output() -> bool {
+    std::env::var_os("DEPOT_VERBOSE_REMOVE").is_some()
+}
+
 /// Installed package row from the local package database.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct InstalledPackageRecord {
@@ -268,8 +272,10 @@ pub fn remove_package(db_path: &Path, name: &str, rootfs: &Path) -> Result<()> {
         let path = rootfs.join(file);
         match fs::remove_file(&path) {
             Ok(()) => {
+                if verbose_remove_output() {
                     crate::log_info!("  Removed file: {}", file);
                 }
+            }
             Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
                 // Already gone, keep going.
             }
@@ -297,14 +303,15 @@ pub fn remove_package(db_path: &Path, name: &str, rootfs: &Path) -> Result<()> {
         )?;
 
         if other_owners > 0 {
-            crate::log_info!("  Keeping directory (owned by other package): {}", dir);
             continue;
         }
 
         // Try to remove (will fail if not empty, which is fine)
         match fs::remove_dir(&path) {
             Ok(()) => {
+                if verbose_remove_output() {
                     crate::log_info!("  Removed directory: {}", dir);
+                }
                 dirs_removed += 1;
             }
             Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
@@ -312,8 +319,10 @@ pub fn remove_package(db_path: &Path, name: &str, rootfs: &Path) -> Result<()> {
             }
             Err(e) if e.raw_os_error() == Some(39) || e.raw_os_error() == Some(66) => {
                 // ENOTEMPTY (39 on Linux, 66 on macOS) - directory not empty
+                if verbose_remove_output() {
                     crate::log_info!("  Keeping directory (not empty): {}", dir);
                 }
+            }
             Err(_) => {
                 // Other errors (permission, etc.) - just skip silently
             }

src/ui.rs

@@ -96,6 +96,10 @@ pub fn set_assume_yes(assume_yes: bool) {
     ASSUME_YES.store(assume_yes, Ordering::Relaxed);
 }
 
+pub fn assume_yes_enabled() -> bool {
+    ASSUME_YES.load(Ordering::Relaxed)
+}
+
 pub fn prompt_yes_no(prompt: &str, default_yes: bool) -> Result<bool> {
     if ASSUME_YES.load(Ordering::Relaxed) {
         info(format!("{} [auto-yes]", prompt));