feat: expose dryrun version in MCP; add schema version

Author: radim

.github/workflows/release.yml

@@ -47,7 +47,7 @@ jobs:
           ext=""
           [ "${{ runner.os }}" = "Windows" ] && ext=".exe"
           CGO_ENABLED=1 go build \
-            -ldflags "-X main.version=${GITHUB_REF_NAME}" \
+            -ldflags "-X github.com/boringsql/dryrun/internal/buildinfo.Version=${GITHUB_REF_NAME}" \
             -o "dryrun${ext}" \
             ./cmd/dryrun
       - name: Archive (tar.xz)

Makefile

@@ -0,0 +1,9 @@
+.PHONY: build clean
+
+VERSION := $(shell git describe --tags --always --dirty 2>/dev/null)
+
+build:
+	go build -ldflags "-X github.com/boringsql/dryrun/internal/buildinfo.Version=$(VERSION)" -o bin/dryrun ./cmd/dryrun
+
+clean:
+	rm -rf bin/

cmd/dryrun/main.go

@@ -7,14 +7,13 @@ import (
 	"log/slog"
 	"os"
 	"path/filepath"
-	"runtime/debug"
 	"sort"
-	"strings"
 
 	"github.com/spf13/cobra"
 
 	mcpserver "github.com/mark3labs/mcp-go/server"
 
+	"github.com/boringsql/dryrun/internal/buildinfo"
 	"github.com/boringsql/dryrun/internal/config"
 	"github.com/boringsql/dryrun/internal/diff"
 	"github.com/boringsql/dryrun/internal/history"
@@ -23,22 +22,6 @@ import (
 	"github.com/boringsql/dryrun/internal/schema"
 )
 
-// version is set via ldflags: -X main.version=v0.1.0
-var version string
-
-func getVersion() string {
-	if version != "" {
-		return version
-	}
-	if info, ok := debug.ReadBuildInfo(); ok {
-		v := info.Main.Version
-		if v != "" && v != "(devel)" && !strings.Contains(v, "0.0.0-") {
-			return v
-		}
-	}
-	return "dev"
-}
-
 var (
 	flagDB         string
 	flagProfile    string
@@ -50,7 +33,7 @@ func main() {
 	root := &cobra.Command{
 		Use:     "dryrun",
 		Short:   "PostgreSQL schema intelligence",
-		Version: getVersion(),
+		Version: buildinfo.Get(),
 	}
 
 	pf := root.PersistentFlags()
@@ -62,14 +45,26 @@ func main() {
 	root.AddCommand(
 		probeCmd(), initCmd(), importCmd(), dumpSchemaCmd(),
 		lintCmd(), driftCmd(), snapshotCmd(), profileCmd(),
-		mcpServeCmd(), statsCmd(),
+		mcpServeCmd(), statsCmd(), versionCmd(),
 	)
 
 	if err := root.Execute(); err != nil {
 		os.Exit(1)
 	}
 }
 
+func versionCmd() *cobra.Command {
+	return &cobra.Command{
+		Use:   "version",
+		Short: "Print dryrun and history schema versions",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			fmt.Printf("dryrun %s\n", buildinfo.Get())
+			fmt.Printf("history schema: v%d\n", history.HistorySchemaVersion)
+			return nil
+		},
+	}
+}
+
 func probeCmd() *cobra.Command {
 	return &cobra.Command{
 		Use:   "probe",
@@ -893,7 +888,7 @@ func mcpServeCmd() *cobra.Command {
 				server.SetUninitialized(candidates)
 			}
 
-			mcpSrv := mcpserver.NewMCPServer("dryrun", getVersion(),
+			mcpSrv := mcpserver.NewMCPServer("dryrun", buildinfo.Get(),
 				mcpserver.WithInstructions(server.Instructions()),
 			)
 			server.Register(mcpSrv)

internal/buildinfo/buildinfo.go

@@ -0,0 +1,26 @@
+package buildinfo
+
+import (
+	"regexp"
+	"runtime/debug"
+)
+
+// set via ldflags: -X github.com/boringsql/dryrun/internal/buildinfo.Version=v0.9.0
+var Version string
+
+// pseudo-version forms v0.0.0-<ts>-<sha> and vX.Y.Z-0.<ts>-<sha>
+var pseudoVersion = regexp.MustCompile(`-(0\.)?\d{14}-[0-9a-f]{12}(\+incompatible)?$`)
+
+func Get() string {
+	if Version != "" {
+		return Version
+	}
+	// go install records the module version; pseudo-versions and "(devel)" are dev builds
+	if info, ok := debug.ReadBuildInfo(); ok {
+		v := info.Main.Version
+		if v != "" && v != "(devel)" && !pseudoVersion.MatchString(v) {
+			return v
+		}
+	}
+	return "dev"
+}

internal/buildinfo/buildinfo_test.go

@@ -0,0 +1,41 @@
+package buildinfo
+
+import "testing"
+
+func TestGetReturnsLdflagsVersion(t *testing.T) {
+	// Get() should hand back whatever ldflags injected, untouched.
+	old := Version
+	t.Cleanup(func() { Version = old })
+
+	Version = "v0.9.0"
+	if got := Get(); got != "v0.9.0" {
+		t.Fatalf("Get() = %q, want v0.9.0", got)
+	}
+}
+
+func TestPseudoVersionMatches(t *testing.T) {
+	// these are the build-info Main.Version strings we must NOT report as a real
+	// version; matching them makes Get() fall through to "dev".
+	pseudo := []string{
+		"v0.0.0-20260530120000-abc123456789",   // untagged repo
+		"v0.9.0-0.20260530120000-abc123456789", // tagged ancestor, newer commit
+		"v1.2.3-0.20260530120000-abc123456789+incompatible",
+	}
+	for _, v := range pseudo {
+		if !pseudoVersion.MatchString(v) {
+			t.Errorf("expected %q to be detected as a pseudo-version", v)
+		}
+	}
+
+	real := []string{
+		"v0.9.0",
+		"v0.8.2",
+		"v1.2.3-rc1",
+		"v2.0.0+incompatible",
+	}
+	for _, v := range real {
+		if pseudoVersion.MatchString(v) {
+			t.Errorf("did not expect %q to match the pseudo-version pattern", v)
+		}
+	}
+}

internal/mcp/server.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/jackc/pgx/v5/pgxpool"
 
+	"github.com/boringsql/dryrun/internal/buildinfo"
 	"github.com/boringsql/dryrun/internal/dryrun"
 	"github.com/boringsql/dryrun/internal/history"
 	"github.com/boringsql/dryrun/internal/lint"
@@ -183,15 +184,17 @@ func (s *Server) Instructions() string {
 		metaNote += "\n\nWarning: " + *note + "."
 	}
 
+	dv := buildinfo.Get()
+
 	snap, err := s.getSchema()
 	if err != nil || snap.PgVersion == "" {
-		return "dryrun PostgreSQL schema advisor. No schema loaded yet.\n\n" + metaNote
+		return fmt.Sprintf("dryrun %s, PostgreSQL schema advisor. No schema loaded yet.\n\n%s", dv, metaNote)
 	}
 
 	ver, err := dryrun.ParsePgVersion(snap.PgVersion)
 	if err != nil {
-		return fmt.Sprintf("dryrun PostgreSQL schema advisor. Database: %s\n\n%s", snap.Database, metaNote)
+		return fmt.Sprintf("dryrun %s, PostgreSQL schema advisor. Database: %s\n\n%s", dv, snap.Database, metaNote)
 	}
 
-	return fmt.Sprintf("dryrun PostgreSQL schema advisor. PostgreSQL %s; database: %s\n\n%s", ver, snap.Database, metaNote)
+	return fmt.Sprintf("dryrun %s, PostgreSQL schema advisor. PostgreSQL %s; database: %s\n\n%s", dv, ver, snap.Database, metaNote)
 }