engine: fix versioning by propagating TAGPREFIX

[wojiushixiaobai]

The gen-ver.sh script (or the version generation logic) fails to capture the correct version because it defaults to a tagregex of v[0-9]*. As shown in the build logs, this causes the versioning logic to either miss the official tags or fail to strip the docker- prefix:

#37 0.060 + tagregex='v[0-9]*'
#37 0.060 ++ git -C /usr/local/src/engine describe --match 'v[0-9]*' --tags
#37 0.095 + version=v2.0.0-beta.9-33-g828f87ccfd

[crazy-max]

LGTM

[thaJeztah]

Wondering if it should be closer to the default, but with a prefix, e.g. docker-v[0-9]*

(no strong opinion, just thinking out loud 😅)

cc @vvoland

[thaJeztah]

(not sure if the * glob would work if set through the arg)

[wojiushixiaobai]

• packaging/hack/scripts/gen-ver.sh

  Lines 18 to 32 in 928861f

  	# optional tag prefix to handle versions like:
  	# cmd/cli/v0.1.44 -> v0.1.44
  	# docker-v29.0.0 -> v29.0.0
  	: "${TAGPREFIX:=}"
  	srcdir="$1"
  	if [ -z "$srcdir" ]; then
  	echo "usage: ./gen-ver <srcdir>" >&2
  	exit 1
  	fi
  	tagregex="${TAGPREFIX}v[0-9]*"
  	version=$(git -C "${srcdir}" describe --match "$tagregex" --tags)
  	commit="$(git --git-dir "${srcdir}/.git" rev-parse HEAD)"
  	commitShort=${commit:0:7}

If we set TAGPREFIX="docker-v[0-9]*", the resulting tagregex becomes docker-v[0-9]*v[0-9]*, which won't match our tags.