feat: inject git describe into dev builds for --version (#208)

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - `lmm game list` — a table of every configured game (ID, name, install path, mod path, deploy mode, and a compact `source:id` rendering of its sources), marking the default game (see `lmm game show-default`) and pointing at `lmm game add`/`lmm game detect` when nothing is configured yet. Supports `--json` like `list`/`search`/`source list` (#205)
+- `make build` (and `make`) now stamp `git describe --tags --dirty` into the binary via `-ldflags -X`, so `lmm --version` on a dev build self-identifies (e.g. `1.28.0 (dev: v1.28.0-2-g140e3c6-dirty)`) instead of showing the same plain `1.28.0` as a release build — the confusion this fixed came up during the v1.28.0 cycle. A build exactly on the release tag (clean) still shows the plain version; a plain `go build`/`go test` (no ldflags) is unaffected. The static `version` var and man pages are untouched by construction (#208)
 
 ### Changed
 

Makefile

@@ -5,7 +5,8 @@ BINARY_NAME := lmm
 BUILD_DIR := ./build
 MAIN_PATH := ./cmd/lmm
 VERSION := $(shell grep 'version = ' cmd/lmm/root.go | cut -d'"' -f2)
-LDFLAGS := -ldflags "-s -w"
+DESCRIBE := $(shell git describe --tags --always --dirty 2>/dev/null)
+LDFLAGS := -ldflags "-s -w -X main.buildDescribe=$(DESCRIBE)"
 # Project-local Go cache so tests run in sandboxed environments (e.g. CI, Cursor)
 GOCACHE_LOCAL := $(CURDIR)/.go-mod/cache
 # Trunk cache under project for sandbox-friendly lint
@@ -16,7 +17,7 @@ all: build
 
 ## build: Build the binary
 build:
-	@echo "Building $(BINARY_NAME) v$(VERSION)..."
+	@echo "Building $(BINARY_NAME) v$(VERSION)$(if $(DESCRIBE), ($(DESCRIBE)))..."
 	@go build $(LDFLAGS) -o $(BINARY_NAME) $(MAIN_PATH)
 
 ## build-debug: Build with debug symbols

README.md

@@ -1122,6 +1122,12 @@ go vet ./...
 go build -o lmm ./cmd/lmm
 ```
 
+`make build` (or `make`) is the preferred way to build a working binary: it
+stamps `git describe --tags --dirty` into the binary, so `lmm --version` on
+a dev build self-identifies as e.g. `1.28.0 (dev: v1.28.0-2-g140e3c6-dirty)`
+instead of silently claiming the last released version. A plain
+`go build`/`go test` (no ldflags) behaves exactly like a clean release build.
+
 ## License
 
 MIT License - See [LICENSE](LICENSE) for details.

cmd/lmm/root.go

@@ -41,6 +41,12 @@ var ErrReported = errors.New("already reported")
 var (
 	version = "1.28.0"
 
+	// buildDescribe is injected at build time via -ldflags -X (see the
+	// Makefile's `build` target) with `git describe --tags --dirty`.
+	// Empty for builds made without that ldflags (plain `go build`/`go
+	// test`), which display identically to a clean release build.
+	buildDescribe = ""
+
 	// Global flags
 	configDir  string
 	dataDir    string
@@ -78,11 +84,25 @@ FILES
                           cache/ (downloaded and extracted mod files), and
                           downloads/ (staging area for in-flight downloads
                           and archive extraction). Override with --data.`,
-	Version:       version,
+	Version:       computeDisplayVersion(version, buildDescribe),
 	SilenceUsage:  true, // Runtime errors should not print usage
 	SilenceErrors: true, // We handle error output in Execute()
 }
 
+// computeDisplayVersion returns the version string shown to the user for
+// `--version`: ver unadorned when buildDescribe is empty (no ldflags, e.g.
+// `go build`/`go test`) or matches "v"+ver exactly (a clean build of the
+// release tag itself), otherwise ver with buildDescribe's git-describe
+// provenance appended - a "-dirty" suffix from `git describe --dirty`
+// passes through inside that unchanged. JSON surfaces must keep emitting
+// the static `version` var, not this - only human-facing display uses it.
+func computeDisplayVersion(ver, describe string) string {
+	if describe == "" || describe == "v"+ver {
+		return ver
+	}
+	return fmt.Sprintf("%s (dev: %s)", ver, describe)
+}
+
 func init() {
 	// Persistent flags available to all commands
 	rootCmd.PersistentFlags().StringVar(&configDir, "config", "", "config directory (default: ~/.config/lmm)")

cmd/lmm/version_test.go

@@ -0,0 +1,62 @@
+package main
+
+import "testing"
+
+// TestDisplayVersion pins the dev-provenance display logic (#208): a build
+// exactly on the release tag (or one made without the Makefile's ldflags,
+// where buildDescribe is empty) shows the plain static version; anything
+// else appends the git-describe provenance, dirty suffix included verbatim.
+func TestDisplayVersion(t *testing.T) {
+	tests := []struct {
+		name          string
+		version       string
+		buildDescribe string
+		want          string
+	}{
+		{
+			name:          "empty buildDescribe (go build/go test without ldflags)",
+			version:       "1.28.0",
+			buildDescribe: "",
+			want:          "1.28.0",
+		},
+		{
+			name:          "clean tag build matches v+version exactly",
+			version:       "1.28.0",
+			buildDescribe: "v1.28.0",
+			want:          "1.28.0",
+		},
+		{
+			name:          "ahead of the tag",
+			version:       "1.28.0",
+			buildDescribe: "v1.28.0-2-g140e3c6",
+			want:          "1.28.0 (dev: v1.28.0-2-g140e3c6)",
+		},
+		{
+			name:          "dirty worktree on the tag itself",
+			version:       "1.28.0",
+			buildDescribe: "v1.28.0-dirty",
+			want:          "1.28.0 (dev: v1.28.0-dirty)",
+		},
+		{
+			name:          "ahead of the tag and dirty",
+			version:       "1.28.0",
+			buildDescribe: "v1.28.0-2-g140e3c6-dirty",
+			want:          "1.28.0 (dev: v1.28.0-2-g140e3c6-dirty)",
+		},
+		{
+			name:          "tag-less clone falls back to a bare hash (git describe --always)",
+			version:       "1.28.0",
+			buildDescribe: "140e3c6",
+			want:          "1.28.0 (dev: 140e3c6)",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := computeDisplayVersion(tt.version, tt.buildDescribe)
+			if got != tt.want {
+				t.Errorf("computeDisplayVersion(%q, %q) = %q, want %q", tt.version, tt.buildDescribe, got, tt.want)
+			}
+		})
+	}
+}