fix(update): select ldd2-35 build on glibc below 2.38 and verify before replace

cmd/update/linux_asset_suffix_linux.go

@@ -13,7 +13,7 @@ import (
 
 const (
 	linuxLdd235Suffix   = "_ldd2-35"
-	linuxGlibcThreshold = "2.36"
+	linuxGlibcThreshold = "2.38"
 )
 
 var glibcVersionPattern = regexp.MustCompile(`(\d+\.\d+)(?:\.\d+)?`)

cmd/update/linux_asset_suffix_linux_test.go

@@ -64,10 +64,22 @@ func TestLinuxAssetSuffixFromGlibcVersion(t *testing.T) {
 		want   string
 	}{
 		{
+			// Ubuntu 22.04 (glibc 2.35) — cannot run the default glibc-2.38 binary.
 			output: "ldd (Ubuntu GLIBC 2.35-0ubuntu3.8) 2.35\n",
 			want:   linuxLdd235Suffix,
 		},
 		{
+			// Debian 12 (glibc 2.36) — cannot run the default glibc-2.38 binary.
+			output: "ldd (Debian GLIBC 2.36-9+deb12u14) 2.36\n",
+			want:   linuxLdd235Suffix,
+		},
+		{
+			// glibc 2.38 — the exact minimum required by the default binary.
+			output: "ldd (GNU libc) 2.38\n",
+			want:   "",
+		},
+		{
+			// Ubuntu 24.04 (glibc 2.39) — can run the default binary.
 			output: "ldd (Ubuntu GLIBC 2.39-0ubuntu8.4) 2.39\n",
 			want:   "",
 		},

cmd/update/replace.go

@@ -0,0 +1,69 @@
+package update
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"os/exec"
+	osruntime "runtime"
+	"strings"
+
+	"github.com/smartcontractkit/cre-cli/internal/ui"
+)
+
+const backupSuffix = ".bak"
+
+func verifyBinaryRuns(binPath string) error {
+	cmd := exec.Command(binPath, "version") // #nosec G204 -- binPath is a verified release artifact
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
+	if err := cmd.Run(); err != nil {
+		if msg := strings.TrimSpace(stderr.String()); msg != "" {
+			return fmt.Errorf("%s", msg)
+		}
+		return err
+	}
+	return nil
+}
+
+func replaceSelf(newBin string) error {
+	self, err := os.Executable()
+	if err != nil {
+		return err
+	}
+	return replaceBinaryAt(self, newBin)
+}
+
+func replaceBinaryAt(self, newBin string) error {
+	if osruntime.GOOS == "windows" {
+		ui.Warning("Automatic replacement not supported on Windows")
+		ui.Dim("Please close all running cre processes and manually replace the binary at:")
+		ui.Code(self)
+		ui.Dim("New binary downloaded at:")
+		ui.Code(newBin)
+		return fmt.Errorf("automatic replacement not supported on Windows")
+	}
+
+	backupPath := self + backupSuffix
+	_ = os.Remove(backupPath)
+
+	if err := os.Rename(self, backupPath); err != nil {
+		return fmt.Errorf("failed to backup current binary: %w", err)
+	}
+
+	if err := os.Rename(newBin, self); err != nil {
+		_ = os.Rename(backupPath, self)
+		return fmt.Errorf("failed to replace binary: %w", err)
+	}
+
+	if err := verifyBinaryRuns(self); err != nil {
+		_ = os.Remove(self)
+		if restoreErr := os.Rename(backupPath, self); restoreErr != nil {
+			return fmt.Errorf("post-install verification failed and could not restore backup: %v (verify error: %w)", restoreErr, err)
+		}
+		return fmt.Errorf("post-install verification failed; restored previous binary: %w", err)
+	}
+
+	_ = os.Remove(backupPath)
+	return nil
+}

cmd/update/replace_test.go

@@ -0,0 +1,95 @@
+package update
+
+import (
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestVerifyBinaryRuns(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("shell scripts used for unix fake binaries")
+	}
+	t.Parallel()
+
+	tmpDir := t.TempDir()
+	binPath := filepath.Join(tmpDir, "cre-test")
+	script := "#!/bin/sh\nexit 0\n"
+	require.NoError(t, os.WriteFile(binPath, []byte(script), 0755))
+
+	require.NoError(t, verifyBinaryRuns(binPath))
+
+	failPath := filepath.Join(tmpDir, "cre-fail")
+	failScript := "#!/bin/sh\necho glibc error >&2\nexit 1\n"
+	require.NoError(t, os.WriteFile(failPath, []byte(failScript), 0755))
+
+	err := verifyBinaryRuns(failPath)
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "glibc error")
+}
+
+func TestReplaceBinaryAt_restoresBackupOnPostInstallFailure(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("unix-only replace flow")
+	}
+
+	tmpDir := t.TempDir()
+	current := filepath.Join(tmpDir, "cre")
+	newBin := filepath.Join(tmpDir, "cre-new")
+
+	currentScript := "#!/bin/sh\necho old\n"
+	require.NoError(t, os.WriteFile(current, []byte(currentScript), 0755))
+
+	newScript := "#!/bin/sh\necho broken >&2\nexit 1\n"
+	require.NoError(t, os.WriteFile(newBin, []byte(newScript), 0755))
+
+	err := replaceBinaryAt(current, newBin)
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "restored previous binary")
+
+	restored, err := os.ReadFile(current)
+	require.NoError(t, err)
+	require.Equal(t, currentScript, string(restored))
+	require.NoFileExists(t, current+backupSuffix)
+}
+
+func TestReplaceBinaryAt_succeedsWithWorkingBinary(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("unix-only replace flow")
+	}
+
+	tmpDir := t.TempDir()
+	current := filepath.Join(tmpDir, "cre")
+	newBin := filepath.Join(tmpDir, "cre-new")
+
+	currentScript := "#!/bin/sh\necho old\n"
+	require.NoError(t, os.WriteFile(current, []byte(currentScript), 0755))
+
+	newScript := "#!/bin/sh\necho new\n"
+	require.NoError(t, os.WriteFile(newBin, []byte(newScript), 0755))
+
+	require.NoError(t, replaceBinaryAt(current, newBin))
+
+	updated, err := os.ReadFile(current)
+	require.NoError(t, err)
+	require.Equal(t, newScript, string(updated))
+	require.NoFileExists(t, current+backupSuffix)
+	require.NoFileExists(t, newBin)
+}
+
+func TestVerifyBinaryRuns_realGoBinary(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		t.Skip("shell scripts used for unix fake binaries")
+	}
+
+	tmpDir := t.TempDir()
+	binPath := filepath.Join(tmpDir, "version-bin")
+	out, err := exec.Command("go", "build", "-o", binPath, "testdata/version_main.go").CombinedOutput()
+	require.NoError(t, err, string(out))
+
+	require.NoError(t, verifyBinaryRuns(binPath))
+}

cmd/update/testdata/version_main.go

@@ -0,0 +1,7 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("test-version")
+}

cmd/update/update.go

@@ -282,24 +282,6 @@ func unzip(assetPath string) (string, error) {
 	return "", errors.New("binary not found in zip")
 }
 
-func replaceSelf(newBin string) error {
-	self, err := os.Executable()
-	if err != nil {
-		return err
-	}
-	// On Windows, need to move after process exit
-	if osruntime.GOOS == "windows" {
-		ui.Warning("Automatic replacement not supported on Windows")
-		ui.Dim("Please close all running cre processes and manually replace the binary at:")
-		ui.Code(self)
-		ui.Dim("New binary downloaded at:")
-		ui.Code(newBin)
-		return fmt.Errorf("automatic replacement not supported on Windows")
-	}
-	// On Unix, can replace in-place
-	return os.Rename(newBin, self)
-}
-
 // Run accepts the currentVersion string and a force flag that overrides the
 // fail-closed behavior when versions cannot be compared.
 func Run(currentVersion string, force bool) error {
@@ -395,11 +377,21 @@ func Run(currentVersion string, force bool) error {
 		return fmt.Errorf("release signature verification failed: %w", err)
 	}
 
-	spinner.Update("Installing...")
 	if err := os.Chmod(binPath, 0755); err != nil {
 		spinner.Stop()
 		return fmt.Errorf("failed to set permissions: %w", err)
 	}
+
+	spinner.Update("Verifying binary...")
+	if err := verifyBinaryRuns(binPath); err != nil {
+		spinner.Stop()
+		if osruntime.GOOS == "linux" {
+			return fmt.Errorf("pre-install binary verification failed: %w; try downloading the compatible build manually: cre_linux_amd64_ldd2-35", err)
+		}
+		return fmt.Errorf("pre-install binary verification failed: %w", err)
+	}
+
+	spinner.Update("Installing...")
 	if err := replaceSelf(binPath); err != nil {
 		spinner.Stop()
 		return fmt.Errorf("failed to replace binary: %w", err)

install/install.sh

@@ -196,7 +196,7 @@ verify_release_binary() {
 }
 
 LINUX_LDD235_SUFFIX="_ldd2-35"
-LINUX_GLIBC_THRESHOLD="2.36"
+LINUX_GLIBC_THRESHOLD="2.38"
 
 parse_glibc_version_from_ldd_output() {
   local output=$1