Allow initializing pool without a buildroot & other minor cleanup

pool_bin

@@ -393,10 +393,10 @@ def pool_info(
             pool_info(function, recursive, subpool)
 
 
-def pool_init(buildroot: str) -> None:
+def pool_init(buildroot: str | None) -> None:
     logger.debug(f"pool_init({buildroot=})")
     try:
-        Pool.init_create(os.path.abspath(buildroot))
+        Pool.init_create(buildroot)
     except PoolError as e:
         if DEBUG:
             raise e
@@ -464,7 +464,7 @@ def main() -> None:
     command = os.path.split(sys.argv[0])[-1]
     sys.argv[0] = PROG
     if command.startswith(PROG + "-"):
-        subcommand = command[len(PROG + "-") :]
+        subcommand = command[len(PROG + "-"):]
         sys.argv.insert(1, subcommand)
 
     env_vars = (
@@ -675,7 +675,20 @@ def main() -> None:
         formatter_class=argparse.RawDescriptionHelpFormatter,
         epilog=env_vars,
     )
-    parser_init.add_argument("buildroot", help="/path/to/build-chroot")
+    parser_init_conflicts = parser_init.add_mutually_exclusive_group()
+    parser_init_conflicts.add_argument(
+        "buildroot",
+        nargs="?",
+        default=None,
+        help="/path/to/build-chroot",
+    )
+    parser_init_conflicts.add_argument(
+        "-N",
+        "--no-buildroot",
+        action="store_true",
+        help="create pool with no buildroot (for pool of pools or pre-built"
+        " packages)"
+    )
     parser_init.set_defaults(func=pool_init)
 
     # pool-list
@@ -743,8 +756,18 @@ def main() -> None:
     if args.cmd:
         func = args.func
         args_dict = vars(args)
+        if args.cmd == "init":
+            # argparse handles error if both buildroot and --no-buildroot, but
+            # to force user to make explicit choice, error if neither set
+            if args.buildroot is None and not args.no_buildroot:
+                fatal(
+                    "pool-init requires one of /path/to/buildroot or"
+                    " --no-buildroot"
+                )
+            # if no_buildroot == True then buildroot is None
+            del args_dict["no_buildroot"]
         # only pass debug for pool-get
-        if func.__name__ != "get" and "debug" in args:
+        if args.cmd != "get" and "debug" in args:
             del args_dict["debug"]
         del args_dict["cmd"]
         del args_dict["func"]
@@ -753,7 +776,10 @@ def main() -> None:
                 fatal(f"{args.outputdir} does not exist")
             elif not isdir(args.outputdir):
                 fatal(f"{args.outputdir} exists, but is not a directory")
-        func(**args_dict)
+        try:
+            func(**args_dict)
+        except PoolError as e:
+            fatal(e)
     else:
         fatal("Subcommand required.", parser.print_help)
 

pool_lib/__init__.py

@@ -110,7 +110,7 @@ def parse_package_filename(filename: str) -> tuple[str, str]:
     return name, version
 
 
-def set_deckdebuild_env(filename: str) -> dict[str, str]:
+def read_pkg_deckdebuild_env(filename: str) -> dict[str, str]:
     """Read 'DECKDEBUILD_*' env vars from file.
 
     Return dict of 'DECKDEBUILD_*' values. Values are read from repo env file
@@ -880,7 +880,12 @@ def __init__(
         if not exists(spath):
             raise PoolError(f"no pool found (POOL_DIR={self.path})")
 
-        self.buildroot = os.readlink(self.path_build_root)
+        self.buildroot: str | None
+        if islink(self.path_build_root):
+            self.buildroot = os.readlink(self.path_build_root)
+        else:
+            self.buildroot = None
+
         self.pkgcache = PackageCache(self.path_pkgcache)
         self.stocks = Stocks(
             self.path_stocks, self.pkgcache, [*recursed_paths, self.path]
@@ -1014,6 +1019,11 @@ def resolve(self, unresolved: RS) -> RS:
     def _build_package_source(
         self, source_path: str, name: str, version: str, source: bool = False
     ) -> None:
+        if self.buildroot is None:
+            raise PoolError(
+                "Cannot build a package in a pool without a buildroot"
+                " configured"
+            )
         build_outputdir = tempfile.mkdtemp(
             dir=self.path_tmp, prefix=f"{name}-{version}."
         )
@@ -1032,7 +1042,9 @@ def _build_package_source(
         if source:
             args.append("--build-source")
         # read DECKDEBUILD_ENV if it exists, but existing env takes precidence
-        build_env = set_deckdebuild_env(join(source_path, "DECKDEBUILD_ENV"))
+        build_env = read_pkg_deckdebuild_env(
+            join(source_path, "DECKDEBUILD_ENV")
+        )
         with in_dir(source_path):
             command = [
                 "/usr/bin/deckdebuild",
@@ -1259,7 +1271,9 @@ def sort(self, key: Callable | None, reverse: bool = False) -> None:
 
     @classmethod
     def init_create(
-        cls: type["Pool"], buildroot: AnyPath, path: AnyPath | None = None
+        cls: type["Pool"],
+        buildroot: AnyPath | None,
+        path: AnyPath | None = None,
     ) -> "Pool":
         if path is None:
             cwd = os.getcwd()
@@ -1280,7 +1294,7 @@ def init_create(
         if isdir(spath):
             raise PoolError("pool already initialized")
 
-        if not isdir(buildroot):
+        if buildroot is not None and not isdir(buildroot):
             raise PoolError(f"buildroot `{buildroot}' is not a directory")
 
         mkdir(path_stocks)
@@ -1311,12 +1325,18 @@ def init_create(
 
         Git.set_gitignore(spath, ["tmp"])
 
-        os.symlink(buildroot, path_build_root)
+        # if set, symlink path_build_root -> buildroot, otherwise touch
+        if buildroot is not None:
+            os.symlink(abspath(buildroot), path_build_root)
+        else:
+            open(path_build_root, "w").close()
 
         return cls(path)
 
     def __init__(
-        self, path: AnyPath | None = None, preserve_buildroot: str = "on-error"
+        self,
+        path: AnyPath | None = None,
+        preserve_buildroot: str | None = "on-error",
     ) -> None:
         kernel = PoolKernel(path, preserve_buildroot=preserve_buildroot)
         if kernel.drop_privileges(pretend=True):