Fall back to dev when git describe prints nothing (closes #74)

The Makefile example in the Go styleguide and in the HTTP server conventions
set VERSION from `git describe --tags --always` alone. Where that prints
nothing (outside a git checkout, or where git is missing or refuses the
checkout), the binary was stamped with an empty version and nothing said so.
Both now read
`VERSION ?= $(or $(shell git describe --tags --always 2>/dev/null),dev)`, and
the comment above each names that condition. A `VERSION` from the environment
or the make command line still takes precedence.

Model: opus-5-5

TODO.md

@@ -21,6 +21,11 @@ fmt-check, and commit.
 
 # Completed Steps
 
+- 2026-10-04: The Makefile examples in the Go styleguide and the HTTP server
+  conventions now fall back to `dev` when `git describe` prints nothing (outside
+  a git checkout, or where git is missing or refuses the checkout), instead of
+  stamping an empty version (issue 74). The canonical `Dockerfile` already fails
+  on a `dev` version when `.git` is in the build context.
 - 2026-10-03: Fixed two defects in the canonical Go `Dockerfile` example (issue
   73). The test phase now uses the Debian Go image, since `-race` needs cgo and
   the alpine image has no C compiler, so the phase failed before running a test.

prompts/CODE_STYLEGUIDE_GO.md

@@ -1,6 +1,6 @@
 ---
 title: Code Styleguide — Go
-last_modified: 2026-10-02
+last_modified: 2026-10-04
 ---
 
 1.  Try to hard wrap long lines at 77 characters or less.
@@ -51,8 +51,10 @@ last_modified: 2026-10-02
     # ?= rather than := so that a `VERSION` build argument takes precedence:
     # where a build stage invokes make, `ARG VERSION` puts it in the
     # environment and `?=` defers to it. Otherwise `git describe` runs, in a
-    # build stage on the `.git` the build context carries.
-    VERSION ?= $(shell git describe --tags --always)
+    # build stage on the `.git` the build context carries. When it prints
+    # nothing (outside a git checkout, or where git is missing or refuses the
+    # checkout), the version falls back to `dev`.
+    VERSION ?= $(or $(shell git describe --tags --always 2>/dev/null),dev)
 
     GOLDFLAGS += -X main.Version=$(VERSION)
 

prompts/GO_HTTP_SERVER_CONVENTIONS.md

@@ -1,6 +1,6 @@
 ---
 title: Go HTTP Server Conventions
-last_modified: 2026-10-02
+last_modified: 2026-10-04
 ---
 
 This document defines the architectural patterns, design decisions, and
@@ -987,8 +987,10 @@ Use ldflags to inject version information at build time:
 # ?= rather than := so that a `VERSION` build argument takes precedence:
 # where a build stage invokes make, `ARG VERSION` puts it in the
 # environment and `?=` defers to it. Otherwise `git describe` runs, in a
-# build stage on the `.git` the build context carries.
-VERSION ?= $(shell git describe --tags --always)
+# build stage on the `.git` the build context carries. When it prints
+# nothing (outside a git checkout, or where git is missing or refuses the
+# checkout), the version falls back to `dev`.
+VERSION ?= $(or $(shell git describe --tags --always 2>/dev/null),dev)
 
 build:
     go build -ldflags "-X main.Version=$(VERSION)" ./cmd/httpd