From 92ba48aae09a44113084fba0dee4f2ba94da90e8 Mon Sep 17 00:00:00 2001
From: moul <94029+moul@users.noreply.github.com>
Date: Fri, 20 Mar 2026 10:11:48 +0000
Subject: [PATCH 1/9] feat(node): add --halt-height flag for coordinated chain
 upgrades

Add a -halt-height flag that stops the node after committing a specific
block height. This enables coordinated chain upgrades where all
validators stop at the same height before upgrading the binary.

Usage:
  gnoland start -halt-height 50000

The node will process blocks normally until it commits block 50000,
then gracefully shut down. Set to 0 (default) to run indefinitely.

Implementation:
- Add haltHeight field to ConsensusState with SetHaltHeight setter
- Add WithHaltHeight node Option (same pattern as WithEarlyStart)
- Check height in finalizeCommit after block is committed
- Register -halt-height flag in gnoland start command
---
 gno.land/cmd/gnoland/start.go  | 11 +++++++++++
 tm2/pkg/bft/consensus/state.go | 17 +++++++++++++++++
 tm2/pkg/bft/node/node.go       | 18 +++++++++++++++++-
 3 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/gno.land/cmd/gnoland/start.go b/gno.land/cmd/gnoland/start.go
index dba40f94fc6..da3f48bc39b 100644
--- a/gno.land/cmd/gnoland/start.go
+++ b/gno.land/cmd/gnoland/start.go
@@ -58,6 +58,7 @@ type startCfg struct {
 	logLevel   string
 	logFormat  string
 	earlyStart bool
+	haltHeight int64
 }
 
 func newStartCmd(io commands.IO) *commands.Command {
@@ -171,6 +172,13 @@ func (c *startCfg) RegisterFlags(fs *flag.FlagSet) {
 		false,
 		"[experimental] start RPC and P2P before genesis time, deferring only consensus",
 	)
+
+	fs.Int64Var(
+		&c.haltHeight,
+		"halt-height",
+		0,
+		"halt the node after committing this block height (0 = run indefinitely)",
+	)
 }
 
 func execStart(ctx context.Context, c *startCfg, io commands.IO) error {
@@ -274,6 +282,9 @@ func execStart(ctx context.Context, c *startCfg, io commands.IO) error {
 	if c.earlyStart {
 		opts = append(opts, node.WithEarlyStart())
 	}
+	if c.haltHeight > 0 {
+		opts = append(opts, node.WithHaltHeight(c.haltHeight))
+	}
 	gnoNode, err := node.DefaultNewNode(cfg, genesisPath, evsw, logger, opts...)
 	if err != nil {
 		return fmt.Errorf("unable to create the Gnoland node, %w", err)
diff --git a/tm2/pkg/bft/consensus/state.go b/tm2/pkg/bft/consensus/state.go
index 9fc068f49a1..642aa7047f1 100644
--- a/tm2/pkg/bft/consensus/state.go
+++ b/tm2/pkg/bft/consensus/state.go
@@ -138,6 +138,9 @@ type ConsensusState struct {
 	doPrevote      func(height int64, round int)
 	setProposal    func(proposal *types.Proposal) error
 
+	// if non-zero, the node will stop after committing this height
+	haltHeight int64
+
 	// closed when we finish shutting down
 	done chan struct{}
 }
@@ -195,6 +198,12 @@ func (cs *ConsensusState) SetLogger(l *slog.Logger) {
 	cs.timeoutTicker.SetLogger(l)
 }
 
+// SetHaltHeight sets the height at which the node will stop after committing.
+// If set to 0, the node runs indefinitely.
+func (cs *ConsensusState) SetHaltHeight(height int64) {
+	cs.haltHeight = height
+}
+
 // SetEventSwitch sets event bus.
 func (cs *ConsensusState) SetEventSwitch(evsw events.EventSwitch) {
 	cs.evsw = evsw
@@ -1402,6 +1411,14 @@ func (cs *ConsensusState) finalizeCommit(height int64) {
 
 	// Log the telemetry
 	cs.logTelemetry(block)
+
+	// Check if we should halt at this height
+	if cs.haltHeight > 0 && height >= cs.haltHeight {
+		cs.Logger.Info("Halt height reached, shutting down", "height", height, "halt_height", cs.haltHeight)
+		if err := osm.Kill(); err != nil {
+			cs.Logger.Error("Failed to halt node", "err", err)
+		}
+	}
 }
 
 // -----------------------------------------------------------------------------
diff --git a/tm2/pkg/bft/node/node.go b/tm2/pkg/bft/node/node.go
index 172276a11bb..7601d17a4ee 100644
--- a/tm2/pkg/bft/node/node.go
+++ b/tm2/pkg/bft/node/node.go
@@ -155,6 +155,15 @@ func WithEarlyStart() Option {
 	}
 }
 
+// WithHaltHeight configures the node to stop after committing the given block height.
+// This is useful for coordinated chain upgrades where all validators need to stop
+// at the same height before upgrading the binary.
+func WithHaltHeight(height int64) Option {
+	return func(n *Node) {
+		n.haltHeight = height
+	}
+}
+
 // ------------------------------------------------------------------------------
 
 // Node is the highest level interface to a full Tendermint node.
@@ -190,7 +199,8 @@ type Node struct {
 	eventStoreService *eventstore.Service
 	firstBlockSignal  <-chan struct{}
 
-	earlyStart bool // start RPC+P2P before genesis time, defer only consensus
+	earlyStart bool  // start RPC+P2P before genesis time, defer only consensus
+	haltHeight int64 // if non-zero, halt after committing this block height
 }
 
 func initDBs(config *cfg.Config, dbProvider DBProvider) (blockStore *store.BlockStore, stateDB dbm.DB, err error) {
@@ -577,6 +587,12 @@ func NewNode(config *cfg.Config,
 		option(node)
 	}
 
+	// Apply halt height to consensus state after options are processed
+	if node.haltHeight > 0 {
+		node.consensusState.SetHaltHeight(node.haltHeight)
+		logger.Info("Halt height configured", "height", node.haltHeight)
+	}
+
 	return node, nil
 }
 

From 6eedad88ef69100f6cb35be573462d285aafb19d Mon Sep 17 00:00:00 2001
From: moul <94029+moul@users.noreply.github.com>
Date: Fri, 20 Mar 2026 10:27:48 +0000
Subject: [PATCH 2/9] test(consensus): add TestSetHaltHeight unit test

---
 tm2/pkg/bft/consensus/state_test.go | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/tm2/pkg/bft/consensus/state_test.go b/tm2/pkg/bft/consensus/state_test.go
index c947875171b..0b4b7c1d655 100644
--- a/tm2/pkg/bft/consensus/state_test.go
+++ b/tm2/pkg/bft/consensus/state_test.go
@@ -1807,3 +1807,26 @@ func TestStateOutputVoteStats(t *testing.T) {
 func subscribe(evsw events.EventSwitch, protoevent events.Event) <-chan events.Event {
 	return events.SubscribeToEvent(evsw, testSubscriber, protoevent)
 }
+
+func TestSetHaltHeight(t *testing.T) {
+	t.Helper()
+
+	cs := &ConsensusState{}
+
+	// Default should be 0 (no halt)
+	if cs.haltHeight != 0 {
+		t.Fatalf("expected default haltHeight to be 0, got %d", cs.haltHeight)
+	}
+
+	// Set halt height
+	cs.SetHaltHeight(100)
+	if cs.haltHeight != 100 {
+		t.Fatalf("expected haltHeight to be 100, got %d", cs.haltHeight)
+	}
+
+	// Set to 0 to disable
+	cs.SetHaltHeight(0)
+	if cs.haltHeight != 0 {
+		t.Fatalf("expected haltHeight to be 0, got %d", cs.haltHeight)
+	}
+}

From 88dade8c85dcb016de853514aae260b5d7079b1e Mon Sep 17 00:00:00 2001
From: moul <94029+moul@users.noreply.github.com>
Date: Wed, 1 Apr 2026 20:58:45 +0000
Subject: [PATCH 3/9] feat: support halt_height in config.toml (settable via
 gnoland config set)

---
 gno.land/cmd/gnoland/start.go |  2 +-
 tm2/pkg/bft/config/config.go  |  4 ++++
 tm2/pkg/bft/node/node.go      | 13 +++++++++----
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/gno.land/cmd/gnoland/start.go b/gno.land/cmd/gnoland/start.go
index 5f5138debe7..a2ff03090ba 100644
--- a/gno.land/cmd/gnoland/start.go
+++ b/gno.land/cmd/gnoland/start.go
@@ -177,7 +177,7 @@ func (c *startCfg) RegisterFlags(fs *flag.FlagSet) {
 		&c.haltHeight,
 		"halt-height",
 		0,
-		"halt the node after committing this block height (0 = run indefinitely)",
+		"halt the node after committing this block height (0 = run indefinitely; overrides config halt_height)",
 	)
 }
 
diff --git a/tm2/pkg/bft/config/config.go b/tm2/pkg/bft/config/config.go
index 29734a69a72..4793860391b 100644
--- a/tm2/pkg/bft/config/config.go
+++ b/tm2/pkg/bft/config/config.go
@@ -324,6 +324,10 @@ type BaseConfig struct {
 
 	// TCP or UNIX socket address for the profiling server to listen on
 	ProfListenAddress string `toml:"prof_laddr" comment:"TCP or UNIX socket address for the profiling server to listen on"`
+
+	// If non-zero, the node will halt after committing this block height.
+	// Useful for coordinated chain upgrades.
+	HaltHeight int64 `toml:"halt_height" comment:"If non-zero, the node will halt after committing this block height.\n Useful for coordinated chain upgrades."`
 }
 
 // DefaultBaseConfig returns a default base configuration for a Tendermint node
diff --git a/tm2/pkg/bft/node/node.go b/tm2/pkg/bft/node/node.go
index 7601d17a4ee..57dd1d9beb5 100644
--- a/tm2/pkg/bft/node/node.go
+++ b/tm2/pkg/bft/node/node.go
@@ -587,10 +587,15 @@ func NewNode(config *cfg.Config,
 		option(node)
 	}
 
-	// Apply halt height to consensus state after options are processed
-	if node.haltHeight > 0 {
-		node.consensusState.SetHaltHeight(node.haltHeight)
-		logger.Info("Halt height configured", "height", node.haltHeight)
+	// Apply halt height: CLI option overrides config file
+	haltHeight := node.haltHeight
+	if haltHeight == 0 {
+		haltHeight = config.BaseConfig.HaltHeight
+	}
+	if haltHeight > 0 {
+		node.haltHeight = haltHeight
+		node.consensusState.SetHaltHeight(haltHeight)
+		logger.Info("Halt height configured", "height", haltHeight)
 	}
 
 	return node, nil

From b6abb2420a8067b1f5169d5ee4cab02dc13557b6 Mon Sep 17 00:00:00 2001
From: moul <94029+moul@users.noreply.github.com>
Date: Wed, 1 Apr 2026 21:00:49 +0000
Subject: [PATCH 4/9] refactor: remove --halt-height flag, use config-only
 (gnoland config set halt_height N)

---
 gno.land/cmd/gnoland/start.go | 10 ----------
 tm2/pkg/bft/node/node.go      | 25 +++++--------------------
 2 files changed, 5 insertions(+), 30 deletions(-)

diff --git a/gno.land/cmd/gnoland/start.go b/gno.land/cmd/gnoland/start.go
index a2ff03090ba..10f74ae1e03 100644
--- a/gno.land/cmd/gnoland/start.go
+++ b/gno.land/cmd/gnoland/start.go
@@ -58,7 +58,6 @@ type startCfg struct {
 	logLevel   string
 	logFormat  string
 	earlyStart bool
-	haltHeight int64
 }
 
 func newStartCmd(io commands.IO) *commands.Command {
@@ -173,12 +172,6 @@ func (c *startCfg) RegisterFlags(fs *flag.FlagSet) {
 		"[experimental] start RPC and P2P before genesis time, deferring only consensus",
 	)
 
-	fs.Int64Var(
-		&c.haltHeight,
-		"halt-height",
-		0,
-		"halt the node after committing this block height (0 = run indefinitely; overrides config halt_height)",
-	)
 }
 
 func execStart(ctx context.Context, c *startCfg, io commands.IO) error {
@@ -282,9 +275,6 @@ func execStart(ctx context.Context, c *startCfg, io commands.IO) error {
 	if c.earlyStart {
 		opts = append(opts, node.WithEarlyStart())
 	}
-	if c.haltHeight > 0 {
-		opts = append(opts, node.WithHaltHeight(c.haltHeight))
-	}
 	gnoNode, err := node.DefaultNewNode(cfg, genesisPath, evsw, logger, opts...)
 	if err != nil {
 		return fmt.Errorf("unable to create the Gnoland node, %w", err)
diff --git a/tm2/pkg/bft/node/node.go b/tm2/pkg/bft/node/node.go
index 57dd1d9beb5..a47873c58d7 100644
--- a/tm2/pkg/bft/node/node.go
+++ b/tm2/pkg/bft/node/node.go
@@ -155,15 +155,6 @@ func WithEarlyStart() Option {
 	}
 }
 
-// WithHaltHeight configures the node to stop after committing the given block height.
-// This is useful for coordinated chain upgrades where all validators need to stop
-// at the same height before upgrading the binary.
-func WithHaltHeight(height int64) Option {
-	return func(n *Node) {
-		n.haltHeight = height
-	}
-}
-
 // ------------------------------------------------------------------------------
 
 // Node is the highest level interface to a full Tendermint node.
@@ -199,8 +190,7 @@ type Node struct {
 	eventStoreService *eventstore.Service
 	firstBlockSignal  <-chan struct{}
 
-	earlyStart bool  // start RPC+P2P before genesis time, defer only consensus
-	haltHeight int64 // if non-zero, halt after committing this block height
+	earlyStart bool // start RPC+P2P before genesis time, defer only consensus
 }
 
 func initDBs(config *cfg.Config, dbProvider DBProvider) (blockStore *store.BlockStore, stateDB dbm.DB, err error) {
@@ -587,15 +577,10 @@ func NewNode(config *cfg.Config,
 		option(node)
 	}
 
-	// Apply halt height: CLI option overrides config file
-	haltHeight := node.haltHeight
-	if haltHeight == 0 {
-		haltHeight = config.BaseConfig.HaltHeight
-	}
-	if haltHeight > 0 {
-		node.haltHeight = haltHeight
-		node.consensusState.SetHaltHeight(haltHeight)
-		logger.Info("Halt height configured", "height", haltHeight)
+	// Apply halt height from config
+	if config.BaseConfig.HaltHeight > 0 {
+		node.consensusState.SetHaltHeight(config.BaseConfig.HaltHeight)
+		logger.Info("Halt height configured", "height", config.BaseConfig.HaltHeight)
 	}
 
 	return node, nil

From 45c5ac8b9f1772eaef4ebc787af356d90769c5c0 Mon Sep 17 00:00:00 2001
From: moul <94029+moul@users.noreply.github.com>
Date: Wed, 1 Apr 2026 21:06:45 +0000
Subject: [PATCH 5/9] fix: remove trailing newline in RegisterFlags

---
 gno.land/cmd/gnoland/start.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/gno.land/cmd/gnoland/start.go b/gno.land/cmd/gnoland/start.go
index 10f74ae1e03..678b9fbff63 100644
--- a/gno.land/cmd/gnoland/start.go
+++ b/gno.land/cmd/gnoland/start.go
@@ -171,7 +171,6 @@ func (c *startCfg) RegisterFlags(fs *flag.FlagSet) {
 		false,
 		"[experimental] start RPC and P2P before genesis time, deferring only consensus",
 	)
-
 }
 
 func execStart(ctx context.Context, c *startCfg, io commands.IO) error {

From f77bcd9e2731e587ba77f976b6cc3127c6a87858 Mon Sep 17 00:00:00 2001
From: moul <94029+moul@users.noreply.github.com>
Date: Thu, 2 Apr 2026 21:14:15 +0000
Subject: [PATCH 6/9] refactor: move halt-height to baseapp, fix
 commit-before-halt bug

Move halt logic from consensus state.go to the existing baseapp.go
mechanism. Fix the original bug where state was not committed before
halt. Replace signal-based halt with osm.Kill() to avoid async
non-determinism (cosmos/cosmos-sdk#16638).

halt_height is set via config.toml (gnoland config set halt_height N).
---
 gno.land/cmd/gnoland/start.go       |  9 +++++
 tm2/pkg/bft/consensus/state.go      | 16 ---------
 tm2/pkg/bft/consensus/state_test.go | 22 ------------
 tm2/pkg/bft/node/node.go            |  6 ----
 tm2/pkg/sdk/baseapp.go              | 53 +++++++++--------------------
 5 files changed, 26 insertions(+), 80 deletions(-)

diff --git a/gno.land/cmd/gnoland/start.go b/gno.land/cmd/gnoland/start.go
index 678b9fbff63..80fea6937d6 100644
--- a/gno.land/cmd/gnoland/start.go
+++ b/gno.land/cmd/gnoland/start.go
@@ -17,6 +17,7 @@ import (
 	"github.com/gnolang/gno/tm2/pkg/bft/config"
 	"github.com/gnolang/gno/tm2/pkg/bft/node"
 	"github.com/gnolang/gno/tm2/pkg/bft/privval"
+	"github.com/gnolang/gno/tm2/pkg/sdk"
 	bft "github.com/gnolang/gno/tm2/pkg/bft/types"
 	"github.com/gnolang/gno/tm2/pkg/commands"
 	"github.com/gnolang/gno/tm2/pkg/events"
@@ -269,6 +270,14 @@ func execStart(ctx context.Context, c *startCfg, io commands.IO) error {
 		return fmt.Errorf("unable to create the Gnoland app, %w", err)
 	}
 
+	// Apply halt height from config to the application
+	if cfg.BaseConfig.HaltHeight > 0 {
+		if baseApp, ok := cfg.LocalApp.(*sdk.BaseApp); ok {
+			baseApp.SetHaltHeight(uint64(cfg.BaseConfig.HaltHeight))
+			logger.Info("Halt height configured", "height", cfg.BaseConfig.HaltHeight)
+		}
+	}
+
 	// Create a default node, with the given setup
 	opts := []node.Option{}
 	if c.earlyStart {
diff --git a/tm2/pkg/bft/consensus/state.go b/tm2/pkg/bft/consensus/state.go
index 52db392fe95..5ef5ae69b64 100644
--- a/tm2/pkg/bft/consensus/state.go
+++ b/tm2/pkg/bft/consensus/state.go
@@ -138,9 +138,6 @@ type ConsensusState struct {
 	doPrevote      func(height int64, round int)
 	setProposal    func(proposal *types.Proposal) error
 
-	// if non-zero, the node will stop after committing this height
-	haltHeight int64
-
 	// closed when we finish shutting down
 	done chan struct{}
 }
@@ -198,12 +195,6 @@ func (cs *ConsensusState) SetLogger(l *slog.Logger) {
 	cs.timeoutTicker.SetLogger(l)
 }
 
-// SetHaltHeight sets the height at which the node will stop after committing.
-// If set to 0, the node runs indefinitely.
-func (cs *ConsensusState) SetHaltHeight(height int64) {
-	cs.haltHeight = height
-}
-
 // SetEventSwitch sets event bus.
 func (cs *ConsensusState) SetEventSwitch(evsw events.EventSwitch) {
 	cs.evsw = evsw
@@ -1412,13 +1403,6 @@ func (cs *ConsensusState) finalizeCommit(height int64) {
 	// Log the telemetry
 	cs.logTelemetry(block)
 
-	// Check if we should halt at this height
-	if cs.haltHeight > 0 && height >= cs.haltHeight {
-		cs.Logger.Info("Halt height reached, shutting down", "height", height, "halt_height", cs.haltHeight)
-		if err := osm.Kill(); err != nil {
-			cs.Logger.Error("Failed to halt node", "err", err)
-		}
-	}
 }
 
 // -----------------------------------------------------------------------------
diff --git a/tm2/pkg/bft/consensus/state_test.go b/tm2/pkg/bft/consensus/state_test.go
index 0b4b7c1d655..751324a4240 100644
--- a/tm2/pkg/bft/consensus/state_test.go
+++ b/tm2/pkg/bft/consensus/state_test.go
@@ -1808,25 +1808,3 @@ func subscribe(evsw events.EventSwitch, protoevent events.Event) <-chan events.E
 	return events.SubscribeToEvent(evsw, testSubscriber, protoevent)
 }
 
-func TestSetHaltHeight(t *testing.T) {
-	t.Helper()
-
-	cs := &ConsensusState{}
-
-	// Default should be 0 (no halt)
-	if cs.haltHeight != 0 {
-		t.Fatalf("expected default haltHeight to be 0, got %d", cs.haltHeight)
-	}
-
-	// Set halt height
-	cs.SetHaltHeight(100)
-	if cs.haltHeight != 100 {
-		t.Fatalf("expected haltHeight to be 100, got %d", cs.haltHeight)
-	}
-
-	// Set to 0 to disable
-	cs.SetHaltHeight(0)
-	if cs.haltHeight != 0 {
-		t.Fatalf("expected haltHeight to be 0, got %d", cs.haltHeight)
-	}
-}
diff --git a/tm2/pkg/bft/node/node.go b/tm2/pkg/bft/node/node.go
index a47873c58d7..172276a11bb 100644
--- a/tm2/pkg/bft/node/node.go
+++ b/tm2/pkg/bft/node/node.go
@@ -577,12 +577,6 @@ func NewNode(config *cfg.Config,
 		option(node)
 	}
 
-	// Apply halt height from config
-	if config.BaseConfig.HaltHeight > 0 {
-		node.consensusState.SetHaltHeight(config.BaseConfig.HaltHeight)
-		logger.Info("Halt height configured", "height", config.BaseConfig.HaltHeight)
-	}
-
 	return node, nil
 }
 
diff --git a/tm2/pkg/sdk/baseapp.go b/tm2/pkg/sdk/baseapp.go
index b8594735b4d..b1383bdc899 100644
--- a/tm2/pkg/sdk/baseapp.go
+++ b/tm2/pkg/sdk/baseapp.go
@@ -7,13 +7,13 @@ import (
 	"runtime/debug"
 	"sort"
 	"strings"
-	"syscall"
 
 	"github.com/gnolang/gno/tm2/pkg/amino"
 	abci "github.com/gnolang/gno/tm2/pkg/bft/abci/types"
 	bft "github.com/gnolang/gno/tm2/pkg/bft/types"
 	dbm "github.com/gnolang/gno/tm2/pkg/db"
 	"github.com/gnolang/gno/tm2/pkg/errors"
+	osm "github.com/gnolang/gno/tm2/pkg/os"
 	"github.com/gnolang/gno/tm2/pkg/std"
 	"github.com/gnolang/gno/tm2/pkg/store"
 )
@@ -901,24 +901,6 @@ func (app *BaseApp) EndBlock(req abci.RequestEndBlock) (res abci.ResponseEndBloc
 func (app *BaseApp) Commit() (res abci.ResponseCommit) {
 	header := app.deliverState.ctx.BlockHeader()
 
-	var halt bool
-
-	switch {
-	case app.haltHeight > 0 && uint64(header.GetHeight()) >= app.haltHeight:
-		halt = true
-
-	case app.haltTime > 0 && header.GetTime().Unix() >= int64(app.haltTime):
-		halt = true
-	}
-
-	if halt {
-		app.halt()
-
-		// Note: State is not actually committed when halted. Logs from Tendermint
-		// can be ignored.
-		return abci.ResponseCommit{}
-	}
-
 	// Write the DeliverTx state which is cache-wrapped and commit the MultiStore.
 	// The write to the DeliverTx state writes all state transitions to the root
 	// MultiStore (app.cms) so when Commit() is called is persists those values.
@@ -946,29 +928,28 @@ func (app *BaseApp) Commit() (res abci.ResponseCommit) {
 
 	// return.
 	res.Data = commitID.Hash
+
+	// Check if we should halt after this commit.
+	if app.haltHeight > 0 && uint64(header.GetHeight()) >= app.haltHeight {
+		app.logger.Info("halt height reached, shutting down", "height", header.GetHeight(), "halt_height", app.haltHeight)
+		app.halt()
+	}
+
 	return
 }
 
-// halt attempts to gracefully shutdown the node via SIGINT and SIGTERM falling
-// back on os.Exit if both fail.
+// halt attempts to gracefully shutdown the node via osm.Kill(),
+// falling back on os.Exit if that fails.
 func (app *BaseApp) halt() {
-	app.logger.Info("halting node per configuration", "height", app.haltHeight, "time", app.haltTime)
-
-	p, err := os.FindProcess(os.Getpid())
-	if err == nil {
-		// attempt cascading signals in case SIGINT fails (os dependent)
-		sigIntErr := p.Signal(syscall.SIGINT)
-		sigTermErr := p.Signal(syscall.SIGTERM)
-
-		if sigIntErr == nil || sigTermErr == nil {
-			return
-		}
+	if err := osm.Kill(); err != nil {
+		app.logger.Error("failed to halt node", "err", err)
+		os.Exit(0)
 	}
+}
 
-	// Resort to exiting immediately if the process could not be found or killed
-	// via SIGINT/SIGTERM signals.
-	app.logger.Info("failed to send SIGINT/SIGTERM; exiting...")
-	os.Exit(0)
+// SetHaltHeight sets the block height at which the node will halt after committing.
+func (app *BaseApp) SetHaltHeight(height uint64) {
+	app.haltHeight = height
 }
 
 func (app *BaseApp) Close() error {

From 9feeab3bd9497c8cbad6d4416fd38be20c159abc Mon Sep 17 00:00:00 2001
From: moul <94029+moul@users.noreply.github.com>
Date: Fri, 3 Apr 2026 14:43:33 +0000
Subject: [PATCH 7/9] refactor: move halt check to BeginBlock and use panic
 instead of signals

---
 tm2/pkg/sdk/baseapp.go | 24 +++++++-----------------
 1 file changed, 7 insertions(+), 17 deletions(-)

diff --git a/tm2/pkg/sdk/baseapp.go b/tm2/pkg/sdk/baseapp.go
index 7a80fc94c2f..d345b84f81e 100644
--- a/tm2/pkg/sdk/baseapp.go
+++ b/tm2/pkg/sdk/baseapp.go
@@ -3,7 +3,6 @@ package sdk
 import (
 	"fmt"
 	"log/slog"
-	"os"
 	"runtime/debug"
 	"sort"
 	"strings"
@@ -13,7 +12,6 @@ import (
 	bft "github.com/gnolang/gno/tm2/pkg/bft/types"
 	dbm "github.com/gnolang/gno/tm2/pkg/db"
 	"github.com/gnolang/gno/tm2/pkg/errors"
-	osm "github.com/gnolang/gno/tm2/pkg/os"
 	"github.com/gnolang/gno/tm2/pkg/std"
 	"github.com/gnolang/gno/tm2/pkg/store"
 )
@@ -526,6 +524,13 @@ func (app *BaseApp) BeginBlock(req abci.RequestBeginBlock) (res abci.ResponseBeg
 		panic(err)
 	}
 
+	// Check if we should halt before processing this block.
+	// We halt at the beginning of the block *after* haltHeight,
+	// so the block at haltHeight is fully committed.
+	if app.haltHeight > 0 && uint64(req.Header.GetHeight()) > app.haltHeight {
+		panic(fmt.Sprintf("halt height %d reached, node shutting down", app.haltHeight))
+	}
+
 	// Initialize the DeliverTx state. If this is the first block, it should
 	// already be initialized in InitChain. Otherwise app.deliverState will be
 	// nil, since it is reset on Commit.
@@ -912,24 +917,9 @@ func (app *BaseApp) Commit() (res abci.ResponseCommit) {
 	// return.
 	res.Data = commitID.Hash
 
-	// Check if we should halt after this commit.
-	if app.haltHeight > 0 && uint64(header.GetHeight()) >= app.haltHeight {
-		app.logger.Info("halt height reached, shutting down", "height", header.GetHeight(), "halt_height", app.haltHeight)
-		app.halt()
-	}
-
 	return
 }
 
-// halt attempts to gracefully shutdown the node via osm.Kill(),
-// falling back on os.Exit if that fails.
-func (app *BaseApp) halt() {
-	if err := osm.Kill(); err != nil {
-		app.logger.Error("failed to halt node", "err", err)
-		os.Exit(0)
-	}
-}
-
 // SetHaltHeight sets the block height at which the node will halt after committing.
 func (app *BaseApp) SetHaltHeight(height uint64) {
 	app.haltHeight = height

From c6ac2158047125576befc7895b9be086f5639009 Mon Sep 17 00:00:00 2001
From: moul <94029+moul@users.noreply.github.com>
Date: Fri, 3 Apr 2026 15:01:18 +0000
Subject: [PATCH 8/9] fix: resolve lint issues (unused haltTime, formatting,
 import order)

---
 gno.land/cmd/gnoland/start.go       | 3 +--
 tm2/pkg/bft/consensus/state.go      | 1 -
 tm2/pkg/bft/consensus/state_test.go | 1 -
 tm2/pkg/sdk/baseapp.go              | 3 ---
 4 files changed, 1 insertion(+), 7 deletions(-)

diff --git a/gno.land/cmd/gnoland/start.go b/gno.land/cmd/gnoland/start.go
index 80fea6937d6..5c015c79033 100644
--- a/gno.land/cmd/gnoland/start.go
+++ b/gno.land/cmd/gnoland/start.go
@@ -17,13 +17,12 @@ import (
 	"github.com/gnolang/gno/tm2/pkg/bft/config"
 	"github.com/gnolang/gno/tm2/pkg/bft/node"
 	"github.com/gnolang/gno/tm2/pkg/bft/privval"
-	"github.com/gnolang/gno/tm2/pkg/sdk"
 	bft "github.com/gnolang/gno/tm2/pkg/bft/types"
 	"github.com/gnolang/gno/tm2/pkg/commands"
 	"github.com/gnolang/gno/tm2/pkg/events"
 	osm "github.com/gnolang/gno/tm2/pkg/os"
 	p2pTypes "github.com/gnolang/gno/tm2/pkg/p2p/types"
-
+	"github.com/gnolang/gno/tm2/pkg/sdk"
 	"github.com/gnolang/gno/tm2/pkg/std"
 	"github.com/gnolang/gno/tm2/pkg/telemetry"
 	"go.uber.org/zap/zapcore"
diff --git a/tm2/pkg/bft/consensus/state.go b/tm2/pkg/bft/consensus/state.go
index e3f831b0205..8c1e0a456ba 100644
--- a/tm2/pkg/bft/consensus/state.go
+++ b/tm2/pkg/bft/consensus/state.go
@@ -1408,7 +1408,6 @@ func (cs *ConsensusState) finalizeCommit(height int64) {
 
 	// Log the telemetry
 	cs.logTelemetry(block)
-
 }
 
 // -----------------------------------------------------------------------------
diff --git a/tm2/pkg/bft/consensus/state_test.go b/tm2/pkg/bft/consensus/state_test.go
index 751324a4240..c947875171b 100644
--- a/tm2/pkg/bft/consensus/state_test.go
+++ b/tm2/pkg/bft/consensus/state_test.go
@@ -1807,4 +1807,3 @@ func TestStateOutputVoteStats(t *testing.T) {
 func subscribe(evsw events.EventSwitch, protoevent events.Event) <-chan events.Event {
 	return events.SubscribeToEvent(evsw, testSubscriber, protoevent)
 }
-
diff --git a/tm2/pkg/sdk/baseapp.go b/tm2/pkg/sdk/baseapp.go
index d345b84f81e..8084e834a82 100644
--- a/tm2/pkg/sdk/baseapp.go
+++ b/tm2/pkg/sdk/baseapp.go
@@ -66,9 +66,6 @@ type BaseApp struct {
 	// block height at which to halt the chain and gracefully shutdown
 	haltHeight uint64
 
-	// minimum block time (in Unix seconds) at which to halt the chain and gracefully shutdown
-	haltTime uint64
-
 	// application's version string
 	appVersion string
 }

From 3237d120e02775772b17bb4926e0a6992f380cba Mon Sep 17 00:00:00 2001
From: moul <94029+moul@users.noreply.github.com>
Date: Fri, 3 Apr 2026 16:52:34 +0000
Subject: [PATCH 9/9] test: add unit tests for halt height behavior

---
 tm2/pkg/sdk/baseapp_test.go | 78 +++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/tm2/pkg/sdk/baseapp_test.go b/tm2/pkg/sdk/baseapp_test.go
index 69298b4ada1..257ce45b3b2 100644
--- a/tm2/pkg/sdk/baseapp_test.go
+++ b/tm2/pkg/sdk/baseapp_test.go
@@ -1273,3 +1273,81 @@ func TestGetMaximumBlockGas(t *testing.T) {
 	app.setConsensusParams(&abci.ConsensusParams{Block: &abci.BlockParams{MaxGas: -5000000}})
 	require.Panics(t, func() { app.getMaximumBlockGas() })
 }
+
+func TestHaltHeight(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name        string
+		haltHeight  uint64
+		blockHeight int64
+		shouldPanic bool
+	}{
+		{
+			name:        "no halt configured",
+			haltHeight:  0,
+			blockHeight: 10,
+			shouldPanic: false,
+		},
+		{
+			name:        "block before halt height",
+			haltHeight:  5,
+			blockHeight: 4,
+			shouldPanic: false,
+		},
+		{
+			name:        "block at halt height processes normally",
+			haltHeight:  5,
+			blockHeight: 5,
+			shouldPanic: false,
+		},
+		{
+			name:        "block after halt height panics",
+			haltHeight:  5,
+			blockHeight: 6,
+			shouldPanic: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			app := setupBaseApp(t)
+			app.SetHaltHeight(tt.haltHeight)
+
+			// Process blocks up to the target height.
+			for h := int64(1); h < tt.blockHeight; h++ {
+				header := &bft.Header{ChainID: "test-chain", Height: h}
+				app.BeginBlock(abci.RequestBeginBlock{Header: header})
+				app.Commit()
+			}
+
+			// Process the target block.
+			header := &bft.Header{ChainID: "test-chain", Height: tt.blockHeight}
+			if tt.shouldPanic {
+				require.Panics(t, func() {
+					app.BeginBlock(abci.RequestBeginBlock{Header: header})
+				})
+			} else {
+				require.NotPanics(t, func() {
+					app.BeginBlock(abci.RequestBeginBlock{Header: header})
+				})
+				app.Commit()
+			}
+		})
+	}
+}
+
+func TestSetHaltHeight(t *testing.T) {
+	t.Parallel()
+
+	app := setupBaseApp(t)
+	require.Equal(t, uint64(0), app.haltHeight)
+
+	app.SetHaltHeight(100)
+	require.Equal(t, uint64(100), app.haltHeight)
+
+	app.SetHaltHeight(0)
+	require.Equal(t, uint64(0), app.haltHeight)
+}