refactor(ci,build,test): rename distro to PKGMGR_DISTRO for consistent environment handling

https://chatgpt.com/share/693d6b63-12cc-800f-b55f-abc52ee7fb52

scripts/build/base.sh

@@ -8,13 +8,13 @@ set -euo pipefail
 : "${BASE_IMAGE_CENTOS:=quay.io/centos/centos:stream9}"
 
 resolve_base_image() {
-  local distro="$1"
-  case "$distro" in
+  local PKGMGR_DISTRO="$1"
+  case "$PKGMGR_DISTRO" in
     arch)   echo "$BASE_IMAGE_ARCH" ;;
     debian) echo "$BASE_IMAGE_DEBIAN" ;;
     ubuntu) echo "$BASE_IMAGE_UBUNTU" ;;
     fedora) echo "$BASE_IMAGE_FEDORA" ;;
     centos) echo "$BASE_IMAGE_CENTOS" ;;
-    *) echo "ERROR: Unknown distro '$distro'" >&2; exit 1 ;;
+    *) echo "ERROR: Unknown distro '$PKGMGR_DISTRO'" >&2; exit 1 ;;
   esac
 }

scripts/build/image.sh

@@ -22,13 +22,13 @@ IS_STABLE="false"    # "true" -> publish stable tags
 DEFAULT_DISTRO="arch"
 
 usage() {
-  local default_tag="pkgmgr-${distro}"
+  local default_tag="pkgmgr-${PKGMGR_DISTRO}"
   if [[ -n "${TARGET:-}" ]]; then
     default_tag="${default_tag}-${TARGET}"
   fi
 
   cat <<EOF
-Usage: distro=<distro> $0 [options]
+Usage: PKGMGR_DISTRO=<distro> $0 [options]
 
 Build options:
   --missing             Build only if the image does not already exist (local build only)
@@ -103,13 +103,13 @@ done
 
 # Derive default local tag if not provided
 if [[ -z "${IMAGE_TAG}" ]]; then
-  IMAGE_TAG="${REPO_PREFIX}-${distro}"
+  IMAGE_TAG="${REPO_PREFIX}-${PKGMGR_DISTRO}"
   if [[ -n "${TARGET}" ]]; then
     IMAGE_TAG="${IMAGE_TAG}-${TARGET}"
   fi
 fi
 
-BASE_IMAGE="$(resolve_base_image "$distro")"
+BASE_IMAGE="$(resolve_base_image "$PKGMGR_DISTRO")"
 
 # Local-only "missing" shortcut
 if [[ "${MISSING_ONLY}" == "1" ]]; then
@@ -141,7 +141,7 @@ fi
 echo
 echo "------------------------------------------------------------"
 echo "[build] Building image"
-echo "distro     = ${distro}"
+echo "distro     = ${PKGMGR_DISTRO}"
 echo "BASE_IMAGE = ${BASE_IMAGE}"
 if [[ -n "${TARGET}" ]]; then echo "target    = ${TARGET}"; fi
 if [[ "${NO_CACHE}" == "1" ]]; then echo "cache     = disabled"; fi
@@ -167,14 +167,14 @@ if [[ -n "${TARGET}" ]]; then
 fi
 
 compute_publish_tags() {
-  local distro_tag_base="${REGISTRY}/${OWNER}/${REPO_PREFIX}-${distro}"
+  local distro_tag_base="${REGISTRY}/${OWNER}/${REPO_PREFIX}-${PKGMGR_DISTRO}"
   local alias_tag_base=""
 
   if [[ -n "${TARGET}" ]]; then
     distro_tag_base="${distro_tag_base}-${TARGET}"
   fi
 
-  if [[ "${distro}" == "${DEFAULT_DISTRO}" ]]; then
+  if [[ "${PKGMGR_DISTRO}" == "${DEFAULT_DISTRO}" ]]; then
     alias_tag_base="${REGISTRY}/${OWNER}/${REPO_PREFIX}"
     if [[ -n "${TARGET}" ]]; then
       alias_tag_base="${alias_tag_base}-${TARGET}"

scripts/build/publish.sh

@@ -30,11 +30,11 @@ echo "[publish] DISTROS=${DISTROS}"
 for d in ${DISTROS}; do
   echo
   echo "============================================================"
-  echo "[publish] distro=${d}"
+  echo "[publish] PKGMGR_DISTRO=${d}"
   echo "============================================================"
 
   # virgin
-  distro="${d}" bash "${SCRIPT_DIR}/image.sh" \
+  PKGMGR_DISTRO="${d}" bash "${SCRIPT_DIR}/image.sh" \
     --publish \
     --registry "${REGISTRY}" \
     --owner "${OWNER}" \
@@ -43,7 +43,7 @@ for d in ${DISTROS}; do
     --target virgin
 
   # full (default target)
-  distro="${d}" bash "${SCRIPT_DIR}/image.sh" \
+  PKGMGR_DISTRO="${d}" bash "${SCRIPT_DIR}/image.sh" \
     --publish \
     --registry "${REGISTRY}" \
     --owner "${OWNER}" \