Verify the nix store before starting a build run.

.gitignore

@@ -3,3 +3,5 @@
 /example_logs
 TODO.org
 /result
+/.envrc
+/.direnv/

migrations/20260725025954_flake_inputs.down.sql

@@ -0,0 +1,2 @@
+DROP INDEX ix_flake_inputs_build_id;
+DROP TABLE flake_inputs;

migrations/20260725025954_flake_inputs.up.sql

@@ -0,0 +1,9 @@
+CREATE TABLE flake_inputs (
+       id INTEGER NOT NULL PRIMARY KEY,
+       build_id INTEGER NOT NULL,
+       input_name TEXT NOT NULL,
+       rev TEXT NOT NULL,
+       FOREIGN KEY(build_id) REFERENCES build(id)
+) STRICT;
+
+CREATE INDEX ix_flake_inputs_build_id ON flake_inputs(build_id);

src/command/build/runner.rs

@@ -1,3 +1,6 @@
+use sqlx::Row;
+use tracing::info;
+
 use crate::Result;
 use crate::cli::parameters::BuildArgs;
 use crate::config::Config;
@@ -7,8 +10,11 @@ use crate::fs_util::assert_directory;
 use crate::fs_util::is_git_repo;
 use crate::git_util::git_force_into_state;
 use crate::git_util::git_init_at_rev;
+use crate::nix_util::FlakeLock;
 use crate::nix_util::nix_flake_update;
+use crate::nix_util::nix_store_verify_repair_check_contents;
 use crate::nix_util::nixos_build_target;
+use crate::nix_util::parse_flake_lock;
 
 pub(crate) async fn run_build(args: BuildArgs) -> Result<()> {
     println!("{:?}", args);
@@ -28,6 +34,8 @@ pub(crate) async fn run_build(args: BuildArgs) -> Result<()> {
 
     let db_handle = DbHandle::new(Some(database_path)).await?;
 
+    verify_nix_store().await?;
+
     for target_name in args.target {
         let target_config = {
             let target_config = config.get_target_config(&target_name)?;
@@ -80,6 +88,12 @@ async fn prepare_flake_repo(config_root: &Config, target_config: &TargetConfig)
     Ok(())
 }
 
+async fn verify_nix_store() -> Result<()> {
+    nix_store_verify_repair_check_contents().await?;
+
+    Ok(())
+}
+
 async fn run_nix_update(config_root: &Config, target_config: &TargetConfig) -> Result<()> {
     let flake_directory = target_config.get_flake_directory(config_root)?;
 
@@ -101,14 +115,61 @@ async fn build_target(
         build_directory.to_string_lossy()
     );
 
+    let target_name = target_config.get_name()?;
+
+    let build_id: i64 = sqlx::query(
+        r#"INSERT INTO build (start_time, target) SELECT unixepoch('now'), ? RETURNING id"#,
+    )
+    .bind(target_name)
+    .fetch_one(&db_handle.conn)
+    .await?
+    .try_get("id")?;
+
+    let flake_lock = parse_flake_lock(&flake_directory).await?;
+    write_input_revs_to_db(db_handle, &flake_lock, build_id).await?;
+
     nixos_build_target(
         db_handle,
         build_directory,
         flake_directory,
         target_config.get_attr()?,
-        target_config.get_name()?,
+        target_name,
+        build_id,
     )
     .await?;
 
     Ok(())
 }
+
+async fn write_input_revs_to_db(
+    db_handle: &DbHandle,
+    flake_lock: &FlakeLock,
+    build_id: i64,
+) -> Result<()> {
+    let root_node = flake_lock.get_root_node()?;
+    let direct_inputs = flake_lock.get_inputs(root_node)?;
+
+    let mut tx = db_handle.conn.begin().await?;
+    for (input, node) in direct_inputs.iter() {
+        let locked = match &node.locked {
+            Some(locked) => locked,
+            None => {
+                info!(
+                    "Not recording rev for input {} because it lacks a locked section.",
+                    input
+                );
+                continue;
+            }
+        };
+        let rev = &locked.rev;
+        info!("input {} {}", input, rev);
+        sqlx::query(r#"INSERT INTO flake_inputs (build_id, input_name, rev) VALUES (?, ?, ?);"#)
+            .bind(build_id)
+            .bind(input)
+            .bind(rev)
+            .execute(&mut *tx)
+            .await?;
+    }
+    tx.commit().await?;
+    Ok(())
+}

src/command/feed_logs/runner.rs

@@ -14,12 +14,10 @@ use crate::nix_util::NixOutputStream;
 use crate::nix_util::OutputLine;
 use crate::nix_util::OutputLineStream;
 use crate::nix_util::RunningBuild;
-use crate::nix_util::RunningUpdate;
 
 pub(crate) async fn feed_logs(args: FeedLogArgs) -> Result<()> {
     let db_handle = DbHandle::new::<String>(None).await?;
-    // let mut running_build = RunningUpdate::new()?;
+    let mut running_build = RunningBuild::new(&db_handle, -1)?;
-    let mut running_build = RunningBuild::new(&db_handle)?;
     let file_stream = FileStream::new(args.input).await?;
     let mut nix_output_stream = NixOutputStream::new(file_stream);
     while let Some(message) = nix_output_stream.next().await? {

src/nix_util/activity.rs

@@ -215,7 +215,15 @@ impl Activity {
                 .as_ref()
                 .map(|phase| Cow::Owned(format!("[{}]", phase))),
             Activity::OptimizeStore(_activity_optimize_store) => None,
-            Activity::VerifyPaths(_activity_verify_paths) => None,
+            Activity::VerifyPaths(activity_verify_paths) => {
+                get_progress_bar(activity_verify_paths.done, activity_verify_paths.expected)
+                    .or_else(|| {
+                        get_progress_text(
+                            activity_verify_paths.done,
+                            activity_verify_paths.expected,
+                        )
+                    })
+            }
             Activity::Substitute(_activity_substitute) => None,
             Activity::QueryPathInfo(_activity_query_path_info) => None,
             Activity::PostBuildHook(_activity_post_build_hook) => None,
@@ -323,8 +331,11 @@ impl Activity {
             Activity::OptimizeStore(_activity_optimize_store) => {
                 panic!("Attempted to set the progress of an optimize store activity.");
             }
-            Activity::VerifyPaths(_activity_verify_paths) => {
+            Activity::VerifyPaths(activity_verify_paths) => {
-                panic!("Attempted to set the progress of a verify paths activity.");
+                activity_verify_paths.done = done;
+                activity_verify_paths.expected = expected;
+                activity_verify_paths.running = running;
+                activity_verify_paths.failed = failed;
             }
             Activity::Substitute(_activity_substitute) => {
                 panic!("Attempted to set the progress of a substitute activity.");
@@ -451,6 +462,10 @@ pub(crate) struct ActivityOptimizeStore {
 }
 pub(crate) struct ActivityVerifyPaths {
     pub(crate) state: ActivityState,
+    pub(crate) done: u64,
+    pub(crate) expected: u64,
+    pub(crate) running: u64,
+    pub(crate) failed: u64,
 }
 pub(crate) struct ActivitySubstitute {
     pub(crate) state: ActivityState,
@@ -493,6 +508,23 @@ impl Default for ActivityState {
 }
 
 fn get_progress_bar(done: u64, expected: u64) -> Option<Cow<'static, str>> {
+    if expected == 0 {
+        return None;
+    }
+    // ○◔◑◕●
+    // ○◎◉●
+    // ▁▂▃▄▅▆▇█
+    // ▏▎▍▌▋▊▉█
+    // ░▒▓█
+    //
+    // 🮷 download
+    // 🮸 upload
+    // 🮵
+    // 🮶
+    get_progress_bar_clockwise_circle(done, expected)
+}
+
+fn get_progress_bar_fade_in(done: u64, expected: u64) -> Option<Cow<'static, str>> {
     if expected == 0 {
         return None;
     }
@@ -520,6 +552,36 @@ fn get_progress_bar(done: u64, expected: u64) -> Option<Cow<'static, str>> {
     }
 }
 
+fn get_progress_bar_clockwise_circle(done: u64, expected: u64) -> Option<Cow<'static, str>> {
+    if expected == 0 {
+        return None;
+    }
+    let percent = done as f32 / expected as f32;
+    // ○◔◑◕●
+    // ○◎◉●
+    // ▁▂▃▄▅▆▇█
+    // ▏▎▍▌▋▊▉█
+    // ░▒▓█
+    //
+    // 🮷 download
+    // 🮸 upload
+    // 🮵
+    // 🮶
+    if percent < 0.25 {
+        Some(Cow::Borrowed("○"))
+    } else if percent < 0.5 {
+        Some(Cow::Borrowed("◔"))
+    } else if percent < 0.75 {
+        Some(Cow::Borrowed("◑"))
+    } else if percent < 1.0 {
+        Some(Cow::Borrowed("◕"))
+    } else if percent >= 1.0 {
+        Some(Cow::Borrowed("●"))
+    } else {
+        None
+    }
+}
+
 fn get_progress_text(done: u64, expected: u64) -> Option<Cow<'static, str>> {
     Some(Cow::Owned(format!("[{}/{}]", done, expected)))
 }

src/nix_util/activity_tree_stream.rs

@@ -163,6 +163,10 @@ impl ActivityTreeStream {
                             activity_start_verify_paths.parent,
                             Activity::VerifyPaths(ActivityVerifyPaths {
                                 state: ActivityState::default(),
+                                done: 0,
+                                expected: 0,
+                                running: 0,
+                                failed: 0,
                             }),
                         )?;
                     }

src/nix_util/high_level.rs

@@ -9,6 +9,7 @@ use crate::Result;
 use crate::database::db_handle::DbHandle;
 
 use super::RunningUpdate;
+use super::RunningVerify;
 use super::running_build::RunningBuild;
 
 pub(crate) async fn nixos_build_target<B, F, A, TN>(
@@ -17,6 +18,7 @@ pub(crate) async fn nixos_build_target<B, F, A, TN>(
     flake_path: F,
     attr: A,
     target_name: TN,
+    build_id: i64,
 ) -> Result<()>
 where
     B: AsRef<Path>,
@@ -55,7 +57,7 @@ where
 
     let child = command.spawn()?;
 
-    let mut running_build = RunningBuild::new(db_handle)?;
+    let mut running_build = RunningBuild::new(db_handle, build_id)?;
     running_build.run_to_completion(child, target_name).await?;
 
     Ok(())
@@ -86,3 +88,26 @@ where
 
     Ok(())
 }
+
+pub(crate) async fn nix_store_verify_repair_check_contents() -> Result<()> {
+    let mut command = Command::new("nix-store");
+    command.stdout(Stdio::piped());
+    command.stderr(Stdio::piped());
+    command.stdin(Stdio::null());
+    command.args([
+        "--verify",
+        "--check-contents",
+        "--repair",
+        "--log-format",
+        "internal-json",
+        "-vvvvvvvvvvv",
+    ]);
+    command.kill_on_drop(true);
+
+    let child = command.spawn()?;
+
+    let mut running_verify = RunningVerify::new()?;
+    running_verify.run_to_completion(child).await?;
+
+    Ok(())
+}

src/nix_util/lock_parser.rs

@@ -0,0 +1,153 @@
+use std::collections::BTreeMap;
+use std::path::Path;
+
+use serde::Deserialize;
+use serde::Serialize;
+
+use crate::Result;
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(deny_unknown_fields)]
+pub(crate) struct FlakeLock {
+    pub(crate) root: String,
+    pub(crate) version: u8,
+    pub(crate) nodes: BTreeMap<String, FlakeLockNode>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(deny_unknown_fields)]
+pub(crate) struct FlakeLockNode {
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub(crate) locked: Option<FlakeLockNodeLocked>,
+
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub(crate) original: Option<FlakeLockNodeOriginal>,
+
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub(crate) inputs: Option<BTreeMap<String, FlakeLockInputValue>>,
+
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub(crate) flake: Option<bool>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(deny_unknown_fields)]
+pub(crate) struct FlakeLockNodeLocked {
+    #[serde(rename = "lastModified")]
+    pub(crate) last_modified: i64,
+
+    #[serde(rename = "narHash")]
+    pub(crate) nar_hash: String,
+
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub(crate) url: Option<String>,
+
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub(crate) owner: Option<String>,
+
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub(crate) repo: Option<String>,
+
+    #[serde(rename = "ref", default, skip_serializing_if = "Option::is_none")]
+    pub(crate) git_ref: Option<String>,
+
+    pub(crate) rev: String,
+
+    #[serde(rename = "revCount", default, skip_serializing_if = "Option::is_none")]
+    pub(crate) rev_count: Option<i64>,
+
+    #[serde(rename = "type")]
+    pub(crate) repo_type: String,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "type", rename_all = "lowercase", deny_unknown_fields)]
+pub(crate) enum FlakeLockNodeOriginal {
+    Github {
+        owner: String,
+
+        repo: String,
+
+        #[serde(rename = "ref", default, skip_serializing_if = "Option::is_none")]
+        git_ref: Option<String>,
+
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        rev: Option<String>,
+    },
+    Git {
+        url: String,
+    },
+    Tarball {
+        url: String,
+    },
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(untagged, deny_unknown_fields)]
+pub(crate) enum FlakeLockInputValue {
+    String(String),
+    List(Vec<String>),
+}
+
+pub(crate) async fn parse_flake_lock<F>(flake_path: F) -> Result<FlakeLock>
+where
+    F: AsRef<Path>,
+{
+    let lock_file_path = flake_path.as_ref().join("flake.lock");
+    let contents = tokio::fs::read_to_string(&lock_file_path).await?;
+    let parsed_flake_lock = serde_json::from_str(&contents)?;
+    Ok(parsed_flake_lock)
+}
+
+impl FlakeLock {
+    pub(crate) fn get_root_node(&self) -> Result<&FlakeLockNode> {
+        let root_node = self.nodes.get(&self.root).ok_or("Root node not found.")?;
+        Ok(root_node)
+    }
+
+    pub(crate) fn get_inputs<'lock>(
+        &'lock self,
+        source_node: &'lock FlakeLockNode,
+    ) -> Result<BTreeMap<&'lock String, &'lock FlakeLockNode>> {
+        let direct_inputs = match &source_node.inputs {
+            Some(inputs) => inputs,
+            None => {
+                return Ok(BTreeMap::new());
+            }
+        };
+        let mut inputs = BTreeMap::new();
+
+        for (input_name, input_id_or_path) in direct_inputs.iter() {
+            inputs.insert(input_name, self.resolve_path(input_id_or_path)?);
+        }
+
+        Ok(inputs)
+    }
+
+    fn resolve_path<'lock>(
+        &'lock self,
+        input_id_or_path: &'lock FlakeLockInputValue,
+    ) -> Result<&'lock FlakeLockNode> {
+        match input_id_or_path {
+            FlakeLockInputValue::String(input_id) => {
+                // If the input value is a plain string, then it refers to a node.
+                let node = self.nodes.get(input_id).ok_or("Input not found.")?;
+                Ok(node)
+            }
+            FlakeLockInputValue::List(items) => {
+                // If the input value is a list, then it refers to a path to an input.
+                let mut current_node = self.get_root_node()?;
+                for step in items {
+                    let child_input_id_or_path = current_node
+                        .inputs
+                        .as_ref()
+                        .ok_or("Node without inputs while walking input tree.")?
+                        .get(step)
+                        .ok_or("Step not found in inputs while walking input tree")?;
+                    current_node = self.resolve_path(child_input_id_or_path)?;
+                }
+                Ok(current_node)
+            }
+        }
+    }
+}

src/nix_util/mod.rs

@@ -2,16 +2,21 @@ mod activity;
 mod activity_tree;
 mod activity_tree_stream;
 mod high_level;
+mod lock_parser;
 mod nix_output_stream;
 mod output_stream;
 mod running_build;
 mod running_update;
+mod running_verify;
 mod tree_iter;
 pub(crate) use activity_tree::ActivityIdAlreadyInTreeError;
 pub(crate) use activity_tree::ActivityIdNotInTreeError;
 pub(crate) use high_level::*;
+pub(crate) use lock_parser::FlakeLock;
+pub(crate) use lock_parser::parse_flake_lock;
 pub(crate) use nix_output_stream::NixOutputStream;
 pub(crate) use output_stream::OutputLine;
 pub(crate) use output_stream::OutputLineStream;
 pub(crate) use running_build::RunningBuild;
 pub(crate) use running_update::RunningUpdate;
+pub(crate) use running_verify::RunningVerify;

src/nix_util/running_build.rs

@@ -21,20 +21,21 @@ use super::nix_output_stream::ActivityResultMessage;
 use super::nix_output_stream::NixMessage;
 use super::tree_iter::DrawDagEntry;
 use super::tree_iter::ReverseTreeIter;
-use super::tree_iter::get_draw_order;
 
 pub(crate) struct RunningBuild<'db> {
     db_handle: &'db DbHandle,
     activity_tree: ActivityTreeStream,
     last_announce: Option<Instant>,
+    build_id: i64,
 }
 
 impl<'db> RunningBuild<'db> {
-    pub(crate) fn new(db_handle: &'db DbHandle) -> Result<Self> {
+    pub(crate) fn new(db_handle: &'db DbHandle, build_id: i64) -> Result<Self> {
         Ok(RunningBuild {
             db_handle,
             activity_tree: ActivityTreeStream::new(),
             last_announce: None,
+            build_id,
         })
     }
 
@@ -46,16 +47,6 @@ impl<'db> RunningBuild<'db> {
     where
         TN: AsRef<str>,
     {
-        let foo = SystemTime::now().duration_since(SystemTime::UNIX_EPOCH)?;
-        let now = Instant::now();
-        let build_id: i64 = sqlx::query(
-            r#"INSERT INTO build (start_time, target) SELECT unixepoch('now'), ? RETURNING id"#,
-        )
-        .bind(target_name.as_ref())
-        .fetch_one(&self.db_handle.conn)
-        .await?
-        .try_get("id")?;
-
         let output_stream = OutputStream::from_child(&mut child)?;
         let mut nix_output_stream: NixOutputStream<OutputStream> =
             NixOutputStream::new(output_stream);
@@ -82,7 +73,7 @@ impl<'db> RunningBuild<'db> {
                         .code()
                         .expect("Process should have an exit code."),
                 )
-                .bind(build_id)
+                .bind(self.build_id)
                 .execute(&self.db_handle.conn)
                 .await?
                 .rows_affected();
@@ -107,7 +98,12 @@ impl<'db> RunningBuild<'db> {
         };
         match message {
             NixAction::Msg(msg_message) => {
-                if msg_message.level > 0 && msg_message.level < 5 {
+                if msg_message.level > 0
+                    && msg_message.level < 5
+                    && !(msg_message.level == 4 && msg_message.msg.starts_with("linking "))
+                    && !(msg_message.level == 4 && msg_message.msg.starts_with("evaluating file "))
+                    && !(msg_message.level == 3 && msg_message.msg.starts_with("checking path "))
+                {
                     eprintln!("LOG MESSAGE {}: {}", msg_message.level, msg_message.msg);
                 }
             }
@@ -129,9 +125,16 @@ impl<'db> RunningBuild<'db> {
                     ActivityResultMessage::SetPhase(_activity_result_set_phase) => {
                         self.print_current_status();
                     }
-                    ActivityResultMessage::Progress(_activity_result_progress) => {
+                    ActivityResultMessage::Progress(activity_result_progress) => {
+                        if activity_result_progress.done == activity_result_progress.expected
+                            && activity_result_progress.expected > 0
+                        {
+                            // If we finished the in-progress activity, always render so we show the 100% done version.
+                            self.print_current_status();
+                        } else {
                             self.maybe_print_current_status();
                         }
+                    }
                     ActivityResultMessage::SetExpected(_activity_result_set_expected) => {
                         self.maybe_print_current_status();
                     }

src/nix_util/running_update.rs

@@ -1,5 +1,4 @@
 use std::borrow::Cow;
-use std::ops::Deref;
 use std::time::Duration;
 use std::time::Instant;
 
@@ -12,7 +11,6 @@ use crate::nix_util::nix_output_stream::NixAction;
 use crate::nix_util::output_stream::OutputStream;
 use crate::nix_util::tree_iter::ForwardTreeIter;
 
-use super::activity::Activity;
 use super::activity_tree::ActivityTreeEntry;
 use super::activity_tree_stream::ActivityTreeStream;
 use super::nix_output_stream::ActivityResultMessage;
@@ -49,7 +47,7 @@ impl RunningUpdate {
         }
 
         let exit_status = exit_status_handle.await?;
-        println!("nix build status was: {}", exit_status);
+        println!("nix update status was: {}", exit_status);
 
         Ok(())
     }
@@ -171,25 +169,8 @@ fn is_match_predicate(entry: &ActivityTreeEntry) -> bool {
     entry.get_activity().get_progress_text().is_some()
 }
 
-pub(crate) fn is_transparent_predicate(entry: &ActivityTreeEntry) -> bool {
+fn is_transparent_predicate(entry: &ActivityTreeEntry) -> bool {
     return false;
-    // match entry.get_activity() {
-    //     Activity::Root(_activity_root) => true,
-    //     Activity::Unknown(_activity_unknown) => false,
-    //     Activity::CopyPath(_activity_copy_path) => false,
-    //     Activity::FileTransfer(_activity_file_transfer) => false,
-    //     Activity::Realize(_activity_realize) => true,
-    //     Activity::CopyPaths(_activity_copy_paths) => true,
-    //     Activity::Builds(_activity_builds) => true,
-    //     Activity::Build(_activity_build) => false,
-    //     Activity::OptimizeStore(_activity_optimize_store) => false,
-    //     Activity::VerifyPaths(_activity_verify_paths) => false,
-    //     Activity::Substitute(_activity_substitute) => false,
-    //     Activity::QueryPathInfo(_activity_query_path_info) => false,
-    //     Activity::PostBuildHook(_activity_post_build_hook) => false,
-    //     Activity::BuildWaiting(_activity_build_waiting) => true,
-    //     Activity::FetchTree(_activity_fetch_tree) => false,
-    // }
 }
 
 fn is_alive_predicate(entry: &ActivityTreeEntry) -> bool {

src/nix_util/running_verify.rs

@@ -0,0 +1,181 @@
+use std::borrow::Cow;
+use std::time::Duration;
+use std::time::Instant;
+
+use tokio::process::Child;
+use tracing::error;
+use tracing::info;
+
+use crate::Result;
+use crate::nix_util::NixOutputStream;
+use crate::nix_util::nix_output_stream::NixAction;
+use crate::nix_util::output_stream::OutputStream;
+use crate::nix_util::tree_iter::ForwardTreeIter;
+
+use super::activity_tree::ActivityTreeEntry;
+use super::activity_tree_stream::ActivityTreeStream;
+use super::nix_output_stream::ActivityResultMessage;
+use super::nix_output_stream::NixMessage;
+
+pub(crate) struct RunningVerify {
+    activity_tree: ActivityTreeStream,
+    last_announce: Option<Instant>,
+}
+
+impl RunningVerify {
+    pub(crate) fn new() -> Result<Self> {
+        Ok(RunningVerify {
+            activity_tree: ActivityTreeStream::new(),
+            last_announce: None,
+        })
+    }
+
+    pub(crate) async fn run_to_completion(&mut self, mut child: Child) -> Result<()> {
+        let output_stream = OutputStream::from_child(&mut child)?;
+        let mut nix_output_stream: NixOutputStream<OutputStream> =
+            NixOutputStream::new(output_stream);
+
+        info!("Verifying nix store.");
+
+        let exit_status_handle = tokio::spawn(async move {
+            let status = child
+                .wait()
+                .await
+                .expect("nixos-rebuild encountered an error");
+            status
+        });
+
+        while let Some(message) = nix_output_stream.next().await? {
+            self.handle_message(message)?;
+        }
+
+        let exit_status = exit_status_handle.await?;
+        info!("nix store verify status was: {}", exit_status);
+
+        Ok(())
+    }
+
+    pub(crate) fn handle_message(&mut self, message: NixMessage) -> Result<()> {
+        self.activity_tree.handle_message(&message)?;
+
+        let message = match message {
+            NixMessage::ParseFailure(line) => {
+                error!("FAIL PARSE: {line}");
+                return Ok(());
+            }
+            NixMessage::Generic(_value, line) => {
+                error!("GENERIC PARSE: {line}");
+                return Ok(());
+            }
+            NixMessage::Action(nix_action) => nix_action,
+        };
+        match message {
+            NixAction::Msg(msg_message) => {
+                // if msg_message.level > 0 && msg_message.level < 5 {
+                //     eprintln!("LOG MESSAGE {}: {}", msg_message.level, msg_message.msg);
+                // }
+            }
+            NixAction::Start(activity_start_message) => {
+                // println!("START: {}", serde_json::to_string(&activity_start_message)?);
+                self.print_current_status();
+            }
+            NixAction::Stop(stop_message) => {
+                // println!("STOP: {}", serde_json::to_string(&stop_message)?);
+                self.print_current_status();
+            }
+            NixAction::Result(activity_result_message) => {
+                match activity_result_message {
+                    ActivityResultMessage::FileLinked(_activity_result_file_linked) => {}
+                    ActivityResultMessage::BuildLogLine(_activity_result_build_log_line) => {}
+                    ActivityResultMessage::UntrustedPath(_activity_result_untrusted_path) => {}
+                    ActivityResultMessage::CorruptedPath(_activity_result_corrupted_path) => {}
+                    ActivityResultMessage::SetPhase(_activity_result_set_phase) => {}
+                    ActivityResultMessage::Progress(activity_result_progress) => {
+                        // if activity_result_progress.expected != 0 {
+                        // println!(
+                        //     "PROGRESS: {}",
+                        //     serde_json::to_string(&activity_result_progress)?
+                        // );
+                        // }
+                        self.maybe_print_current_status();
+                    }
+                    ActivityResultMessage::SetExpected(activity_result_set_expected) => {
+                        // if activity_result_set_expected.expected != 0 {
+                        // println!(
+                        //     "EXPECTED: {}",
+                        //     serde_json::to_string(&activity_result_set_expected)?
+                        // );
+                        // }
+                        self.maybe_print_current_status();
+                    }
+                    ActivityResultMessage::PostBuildLogLine(
+                        _activity_result_post_build_log_line,
+                    ) => {}
+                    ActivityResultMessage::FetchStatus(_activity_result_fetch_status) => {}
+                };
+            }
+        };
+        Ok(())
+    }
+
+    fn maybe_print_current_status(&mut self) -> () {
+        let last_announce = match self.last_announce {
+            Some(instant) => instant,
+            None => {
+                // If we haven't announced before, always announce.
+                return self.print_current_status();
+            }
+        };
+
+        let now = Instant::now();
+        let time_since_last_announce = now.duration_since(last_announce);
+        if time_since_last_announce > Duration::new(5, 0) {
+            return self.print_current_status();
+        }
+    }
+
+    fn print_current_status(&mut self) -> () {
+        let nodes = ForwardTreeIter::new(
+            self.activity_tree.get_tree(),
+            None,
+            is_match_predicate,
+            is_transparent_predicate,
+            is_alive_predicate,
+        );
+        let mut out = Vec::new();
+        for (depth, _is_match, _is_transparent, node) in nodes {
+            let progress_text = node
+                .get_activity()
+                .get_progress_text()
+                .unwrap_or(Cow::Borrowed(""));
+            let name = node
+                .get_activity()
+                .display_name()
+                .unwrap_or(Cow::Borrowed("null"));
+            out.push(format!("{depth}\t{progress_text}\t{name}"))
+        }
+
+        if out.is_empty() {
+            println!("No active activities.");
+        } else {
+            println!("\n");
+            for l in out {
+                println!("{l}\n");
+            }
+            println!("\n");
+        }
+        self.last_announce = Some(Instant::now());
+    }
+}
+
+fn is_match_predicate(entry: &ActivityTreeEntry) -> bool {
+    entry.get_activity().get_progress_text().is_some()
+}
+
+pub(crate) fn is_transparent_predicate(entry: &ActivityTreeEntry) -> bool {
+    return false;
+}
+
+fn is_alive_predicate(entry: &ActivityTreeEntry) -> bool {
+    entry.get_activity().is_active()
+}