use rel as part as version, pkgver now run just following extract source

DEBBUILD

@@ -1,7 +1,9 @@
 #/usr/bin/env bash
 
 pkgname="forgejo"
+pkgver=23333    # this will be override by pkgver function
 pkgrel=1
+pkgcommit=""
 pkgdesc="A painless selfhost git service."
 url="https://codeberg.org/forgejo/forgejo"
 maintainer="Leafee98 <me@leafee98.com>"
@@ -14,8 +16,9 @@ source=(
     "t.sh::material/t.sh"
 )
 
+# This will be run just follow extracting source
 function pkgver {
-    echo "0.0.2"
+    echo "1.19.0-2"
 }
 
 function build {

makedeb

@@ -1,14 +1,13 @@
 #!/usr/bin/env bash
 
-workspace=$(pwd -P)
+workspace="$(pwd -P)"
+buildfile="${workspace}/DEBBUILD"
 
-export srcdir="${workspace}/src"
+srcdir="${workspace}/src"
-export pkgdir="${workspace}/pkg"
+pkgdir="${workspace}/pkg"
 
 FAKE_PACKAGE=0
 OVERRIDE_SOURCE=0
-OVERRIDE_VERSION=""
-ACTION=""
 
 
 set -o functrace
@@ -17,7 +16,6 @@ set -o errtrace
 set -o errexit
 
 function err_occur {
-    err "Build aborted in: %s" "${ACTION}"
     err "Failed at $1: ${BASH_COMMAND}"
     err "Trace line number: %s" "$*"
 }
@@ -54,13 +52,28 @@ function err {
     printf "${RED}  ->${ALL_OFF}${BOLD}${RED} ${mesg}${ALL_OFF}\n" "$@" >&2
 }
 
+function get_full_version {
+    local result="${pkgver//-/.}"
+    if [[ -n "${pkgrel:-}" ]] ; then
+        result="${result}-${pkgrel}"
+    fi
+    if [[ -n "${pkgcommit:-}" ]] ; then
+        result="${result}+${pkgcommit}"
+    fi
+    echo "${result}"
+}
+
+function get_deb_name {
+    echo "${pkgname}_$(get_full_version).deb"
+}
 
 function debian_control {
     local install_size="$(du --block-size=1K --summarize ${pkgdir} | cut -d $'\t' -f 1)"
+    local fv="$(get_full_version)"
 
     cat << EOF | envsubst
 Package: ${pkgname}
-Version: ${pkgver}
+Version: ${fv}
 Architecture: all
 Maintainer: ${maintainer}
 Installed-Size: ${install_size}
@@ -82,9 +95,11 @@ function generate_deb {
 
     echo 2.0 > "${debian_binary}"
 
-    ar r "${pkgname}${pkgver:+-}${pkgver}.deb" "${debian_binary}" "${control_tgz}" "${data_tgz}"
+    ar r "$(get_deb_name)" "${debian_binary}" "${control_tgz}" "${data_tgz}"
 
     rm -rf "${tmpdir}"
+
+    msg2 "generated deb: %s" "$(get_deb_name)"
 }
 
 function url_type {
@@ -257,6 +272,34 @@ function decompress_source_file {
     esac
 }
 
+error_function() {
+	# first exit all subshells, then print the error
+	if (( ! BASH_SUBSHELL )); then
+		error "A failure occurred in %s()." "$1"
+		plainerr "$(gettext "Aborting...")"
+	fi
+	exit $E_USER_FUNCTION_FAILED
+}
+
+# use less strict shell for custom functions
+function run_function_safe {
+	local restoretrap
+
+    set +o errtrace
+    set +o errexit
+
+	restoretrap=$(trap -p ERR)
+	trap "error_function '$1'" ERR
+
+	"$1"
+
+    set -o errtrace
+    set -o errexit
+
+	trap - ERR
+	eval "$restoretrap"
+}
+
 function is_function {
     declare -F "$1" > /dev/null
 }
@@ -270,28 +313,23 @@ while (( "$#" >= 1 )); do
     case "$1" in
         -F)  FAKE_PACKAGE=1 ;;
         -OS) OVERRIDE_SOURCE=1 ;;
-        -OV) OVERRIDE_VERSION="$2"; shift ;;
         *)   err "Unkown option $1"; break ;;
     esac
     shift
 done
 
-source "${workspace}/DEBBUILD"
+source "${buildfile}"
 
 # Run package and generate deb and exit
 if (( FAKE_PACKAGE )); then
-    # version passed directly from parent shell
-    if [[ -n "${OVERRIDE_VERSION}" ]] ; then
-        pkgver="${OVERRIDE_VERSION}"
-    fi
 
     if is_function package; then
-        ACTION="custom package"; msg "run function: %s..." "${ACTION}"
+        msg "run function: custom package..."
-        package
+        run_function_safe package
     fi
 
 
-    ACTION="generating control info"; msg "${ACTION}..."
+    msg "generating control info..."
     mkdir -p "${pkgdir}/DEBIAN"
     echo 2 > "${pkgdir}/DEBIAN/compat"
     debian_control > "${pkgdir}/DEBIAN/control"
@@ -303,7 +341,7 @@ if (( FAKE_PACKAGE )); then
     debian_hooks_warpper debian_postrm   ${pkgdir}/DEBIAN/postrm
 
 
-    ACTION="generating deb package"; msg "${ACTION}..."
+    msg "generating deb package..."
     generate_deb
     exit $?
 fi
@@ -316,12 +354,12 @@ for s in "${source[@]}"; do
     fi
 done
 
-ACTION="cleaning \$srcdir and \$pkgdir"; msg "${ACTION}..."
+msg "cleaning \$srcdir and \$pkgdir..."
 rm -rf "${srcdir}" "${pkgdir}"
 
 mkdir -p "${srcdir}" "${pkgdir}"
 
-ACTION="retrieving source"; msg "${ACTION}..."
+msg "retrieving source..."
 for s in "${source[@]}"; do
     file_name="${s%%::*}"
     url="${s##*::}"
@@ -329,7 +367,7 @@ for s in "${source[@]}"; do
     retrive_source_single "${file_name}" "${url}"
 done
 
-ACTION="extracting source"; msg "${ACTION}..."
+msg "extracting source..."
 for s in "${source[@]}"; do
     file_name="${s%%::*}"
     url="${s##*::}"
@@ -337,23 +375,37 @@ for s in "${source[@]}"; do
     extract_source_single "${file_name}" "${url}"
 done
 
-if is_function build; then
+if is_function pkgver; then
-    ACTION="custom build"; msg "run function: %s..." "${ACTION}"
+    msg "run function: pkgver..."
-    build
+    newpkgver="$(run_function_safe pkgver)"
+    if [[ "${newpkgver}" != "${pkgver:-}" ]] ; then
+        mapfile -t bfcontent < "${buildfile}"
+
+        shopt -s extglob
+        bfcontent=("${bfcontent[@]/#pkgver=*?(")([^ ])?(")/pkgver=$newpkgver}")
+        bfcontent=("${bfcontent[@]/#pkgrel=*([^ ])/pkgrel=1}")
+        shopt -u extglob
+
+        if ! printf '%s\n' "${bfcontent[@]}" > "${buildfile}"; then
+            err "Failed to update %s from %s to %s" "pkgver" "$pkgver" "$newpkgver"
+            exit 1
         fi
 
-ACTION="custom pkgver";
+        source "${buildfile}"
-if [[ -n "${OVERRIDE_VERSION}" ]] ; then
+
-    msg "Using override version: %s" "${OVERRIDE_VERSION}"
+        msg2 "updated version: ${newpkgver}"
-    pkgver="${OVERRIDE_VERSION}"
+    fi
-elif is_function pkgver; then
+    pkgver="${newpkgver}"
-    msg "run function: %s..." "${ACTION}"
+fi
-    pkgver="$(pkgver)"
+
+if is_function build; then
+    msg "run function: custom build..."
+    run_function_safe build
 fi
 
 # recursive call self to run rest task in fakeroot
 msg "entering fakeroot environment..."
-fakeroot -- bash -$- "${BASH_SOURCE[0]}" -F -OV "${pkgver}"  "${ARGLIST[@]}" || exit $?
+fakeroot -- bash -$- "${BASH_SOURCE[0]}" -F "${ARGLIST[@]}" || exit $?
 msg "leaving fakeroot environment..."
 
 msg "builds has done"