feat: Add stages to yashchiki script

Change-Id: Idfeabac17d39bc351c845c002681d7e7f9e7286f

bin/yashchiki

@@ -51,6 +51,8 @@ parser = argparse.ArgumentParser(
               to OUTPUT.
     """))
 
+all_stages=["fetch", "build-base", "build-spack", "image"]
+
 all_styles = list(os.listdir(os.path.dirname(os.path.realpath(__file__)) + "/../share/yashchiki/styles/"))
 
 # mandatory
@@ -67,6 +69,9 @@ parser.add_argument(
 parser.add_argument(
     "--update-build-cache", action="store_true",
     help="Update build cache.")
+parser.add_argument(
+    "--stages", type=str, nargs="+", choices=all_stages, default=all_stages,
+    help="Stages of build to perform.")
 # optional with persistent default
 parser.add_argument(
     "--caches-dir", type=pathlib.Path,
@@ -179,6 +184,22 @@ env.update({
     "YASHCHIKI_JOBS": str(args.jobs),
 })
 
+if "fetch" in args.stages:
+    env.update({"YASHCHIKI_ENABLE_STAGE_FETCH": "1"})
+
+if "build-base" in args.stages:
+    env.update({"YASHCHIKI_ENABLE_STAGE_BUILD_BASE": "1"})
+
+if "build-spack" in args.stages:
+    env.update({"YASHCHIKI_ENABLE_STAGE_BUILD_SPACK": "1"})
+
+if "image" in args.stages:
+    env.update({"YASHCHIKI_ENABLE_STAGE_IMAGE": "1"})
+
+if args.stages != all_stages:
+    if not pathlib.Path(args.sandboxes_dir, args.style).exists():
+        raise RuntimeError("Using yashchiki with incomplete set of stages is only possible for using an existing sandbox.")
+
 if args.build_cache_on_failure_name:
     env.update({"YASHCHIKI_BUILD_CACHE_ON_FAILURE_NAME": args.build_cache_on_failure_name})
 

lib/yashchiki/fetch.sh

@@ -6,6 +6,11 @@ shopt -s inherit_errexit
 SOURCE_DIR="$(dirname "$(readlink -m "${BASH_SOURCE[0]}")")"
 source "${SOURCE_DIR}/commons.sh"
 
+if [ -z "${YASHCHIKI_ENABLE_STAGE_FETCH:-}" ]; then
+    echo "Skipping stage fetch."
+    exit 0
+fi
+
 # temporary spack config scope directory for fetching
 tmp_config_scope=("$(mktemp -d)")