refactor: replace eval_nix/build_nix with machine.select()

- Remove nix(), eval_nix(), and build_nix() methods from Machine class
- Add select() method that handles machine-specific attribute prefixes
- Update all usages to use machine.select() directly
- Handle Path conversion and tmp_store logic at call sites
- This simplifies the Machine API and prepares for deployment.json removal

pkgs/clan-cli/clan_cli/tests/test_vars.py

@@ -992,7 +992,7 @@ def test_dynamic_invalidation(
     # before generating, dependent generator validation should be empty; see bogus hardware-configuration.nix above
     # we have to avoid `*.files.value` in this initial select because the generators haven't been run yet
     # Generators 0: The initial generators before any 'vars generate'
-    generators_0 = machine.eval_nix(f"{gen_prefix}.*.{{validationHash}}")
+    generators_0 = machine.select(f"{gen_prefix}.*.{{validationHash}}")
     assert generators_0["dependent_generator"]["validationHash"] is None
 
     # generate both my_generator and (the dependent) dependent_generator
@@ -1001,7 +1001,7 @@ def test_dynamic_invalidation(
 
     # after generating once, dependent generator validation should be set
     # Generators_1: The generators after the first 'vars generate'
-    generators_1 = machine.eval_nix(gen_prefix)
+    generators_1 = machine.select(gen_prefix)
     assert generators_1["dependent_generator"]["validationHash"] is not None
 
     # @tangential: after generating once, neither generator should want to run again because `clan vars generate` should have re-evaluated the dependent generator's validationHash after executing the parent generator but before executing the dependent generator
@@ -1014,7 +1014,7 @@ def test_dynamic_invalidation(
     cli.run(["vars", "generate", "--flake", str(flake.path), machine.name])
     clan_flake.invalidate_cache()
     # Generators_2: The generators after the second 'vars generate'
-    generators_2 = machine.eval_nix(gen_prefix)
+    generators_2 = machine.select(gen_prefix)
     assert (
         generators_1["dependent_generator"]["validationHash"]
         == generators_2["dependent_generator"]["validationHash"]

pkgs/clan-cli/clan_cli/vars/generate.py

@@ -72,14 +72,20 @@ class Generator:
 
     def final_script(self) -> Path:
         assert self._machine is not None
-        final_script = self._machine.build_nix(
-            f'config.clan.core.vars.generators."{self.name}".finalScript'
+        from clan_lib.nix import nix_test_store
+
+        output = Path(
+            self._machine.select(
+                f'config.clan.core.vars.generators."{self.name}".finalScript'
+            )
         )
-        return final_script
+        if tmp_store := nix_test_store():
+            output = tmp_store.joinpath(*output.parts[1:])
+        return output
 
     def validation(self) -> str | None:
         assert self._machine is not None
-        return self._machine.eval_nix(
+        return self._machine.select(
             f'config.clan.core.vars.generators."{self.name}".validationHash'
         )
 

pkgs/clan-cli/clan_cli/vars/secret_modules/password_store.py

@@ -33,7 +33,7 @@ class SecretStore(StoreBase):
 
     @property
     def _store_backend(self) -> str:
-        backend = self.machine.eval_nix("config.clan.core.vars.settings.passBackend")
+        backend = self.machine.select("config.clan.core.vars.settings.passBackend")
         return backend
 
     @property

pkgs/clan-cli/clan_cli/vms/inspect.py

@@ -55,7 +55,7 @@ class VmConfig:
 
 
 def inspect_vm(machine: Machine) -> VmConfig:
-    data = machine.eval_nix("config.clan.core.vm.inspect")
+    data = machine.select("config.clan.core.vm.inspect")
     # HACK!
     data["flake_url"] = dataclasses.asdict(machine.flake)
     return VmConfig.from_json(data)

pkgs/clan-cli/clan_cli/vms/run.py

@@ -49,16 +49,24 @@ def facts_to_nixos_config(facts: dict[str, dict[str, bytes]]) -> dict:
 
 
 # TODO move this to the Machines class
-def build_vm(machine: Machine, tmpdir: Path) -> dict[str, str]:
+def build_vm(
+    machine: Machine, tmpdir: Path, nix_options: list[str] | None = None
+) -> dict[str, str]:
     # TODO pass prompt here for the GTK gui
-
+    if nix_options is None:
+        nix_options = []
     secrets_dir = get_secrets(machine, tmpdir)
 
-    public_facts = machine.public_facts_store.get_all()
+    from clan_lib.nix import nix_test_store
 
-    nixos_config_file = machine.build_nix(
-        "config.system.clan.vm.create", extra_config=facts_to_nixos_config(public_facts)
+    output = Path(
+        machine.select(
+            "config.system.clan.vm.create",
+        )
     )
+    if tmp_store := nix_test_store():
+        output = tmp_store.joinpath(*output.parts[1:])
+    nixos_config_file = output
     try:
         vm_data = json.loads(Path(nixos_config_file).read_text())
         vm_data["secrets_dir"] = str(secrets_dir)

pkgs/clan-cli/clan_lib/backups/create.py

@@ -4,7 +4,7 @@ from clan_lib.machines.machines import Machine
 
 def create_backup(machine: Machine, provider: str | None = None) -> None:
     machine.info(f"creating backup for {machine.name}")
-    backup_scripts = machine.eval_nix("config.clan.core.backups")
+    backup_scripts = machine.select("config.clan.core.backups")
     host = machine.target_host()
     if provider is None:
         if not backup_scripts["providers"]:

pkgs/clan-cli/clan_lib/backups/list.py

@@ -15,7 +15,7 @@ class Backup:
 
 def list_provider(machine: Machine, host: Remote, provider: str) -> list[Backup]:
     results = []
-    backup_metadata = machine.eval_nix("config.clan.core.backups")
+    backup_metadata = machine.select("config.clan.core.backups")
     list_command = backup_metadata["providers"][provider]["list"]
     proc = host.run(
         [list_command],
@@ -41,7 +41,7 @@ def list_provider(machine: Machine, host: Remote, provider: str) -> list[Backup]
 
 
 def list_backups(machine: Machine, provider: str | None = None) -> list[Backup]:
-    backup_metadata = machine.eval_nix("config.clan.core.backups")
+    backup_metadata = machine.select("config.clan.core.backups")
     results = []
     with machine.target_host().ssh_control_master() as host:
         if provider is None:

pkgs/clan-cli/clan_lib/backups/restore.py

@@ -7,8 +7,8 @@ from clan_lib.ssh.remote import Remote
 def restore_service(
     machine: Machine, host: Remote, name: str, provider: str, service: str
 ) -> None:
-    backup_metadata = machine.eval_nix("config.clan.core.backups")
-    backup_folders = machine.eval_nix("config.clan.core.state")
+    backup_metadata = machine.select("config.clan.core.backups")
+    backup_folders = machine.select("config.clan.core.state")
 
     if service not in backup_folders:
         msg = f"Service {service} not found in configuration. Available services are: {', '.join(backup_folders.keys())}"
@@ -60,7 +60,7 @@ def restore_backup(
     errors = []
     with machine.target_host().ssh_control_master() as host:
         if service is None:
-            backup_folders = machine.eval_nix("config.clan.core.state")
+            backup_folders = machine.select("config.clan.core.state")
             for _service in backup_folders:
                 try:
                     restore_service(machine, host, name, provider, _service)

pkgs/clan-cli/clan_lib/machines/machines.py

@@ -81,9 +81,10 @@ class Machine:
 
     @property
     def deployment(self) -> dict:
-        deployment = json.loads(
-            self.build_nix("config.system.clan.deployment.file").read_text()
-        )
+        output = Path(self.select("config.system.clan.deployment.file"))
+        if tmp_store := nix_test_store():
+            output = tmp_store.joinpath(*output.parts[1:])
+        deployment = json.loads(output.read_text())
         return deployment
 
     @cached_property
@@ -159,13 +160,13 @@ class Machine:
 
         return None
 
-    def nix(
+    def select(
         self,
         attr: str,
     ) -> Any:
         """
-        Build the machine and return the path to the result
-        accepts a secret store and a facts store # TODO
+        Select a nix attribute of the machine
+        @attr: the attribute to get
         """
 
         config = nix_config()
@@ -175,36 +176,6 @@ class Machine:
             f'clanInternals.machines."{system}"."{self.name}".{attr}'
         )
 
-    def eval_nix(self, attr: str, extra_config: None | dict = None) -> Any:
-        """
-        eval a nix attribute of the machine
-        @attr: the attribute to get
-        """
-
-        if extra_config:
-            log.warning("extra_config in eval_nix is no longer supported")
-
-        return self.nix(attr)
-
-    def build_nix(self, attr: str, extra_config: None | dict = None) -> Path:
-        """
-        build a nix attribute of the machine
-        @attr: the attribute to get
-        """
-
-        if extra_config:
-            log.warning("extra_config in build_nix is no longer supported")
-
-        output = self.nix(attr)
-        output = Path(output)
-        if tmp_store := nix_test_store():
-            output = tmp_store.joinpath(*output.parts[1:])
-        assert output.exists(), f"The output {output} doesn't exist"
-        if isinstance(output, Path):
-            return output
-        msg = "build_nix returned not a Path"
-        raise ClanError(msg)
-
 
 @dataclass(frozen=True)
 class RemoteSource:
@@ -229,7 +200,7 @@ def get_host(
         machine.debug(
             f"'{field}' is not set in inventory, falling back to slower Nix config, set it either through the Nix or json interface to improve performance"
         )
-        host_str = machine.eval_nix(f'config.clan.core.networking."{field}"')
+        host_str = machine.select(f'config.clan.core.networking."{field}"')
         source = "nix_machine"
 
     if not host_str:

pkgs/clan-cli/clan_lib/tests/test_create.py

@@ -282,5 +282,5 @@ def test_clan_create_api(
     clan_dir_flake.invalidate_cache()
 
     with pytest.raises(ClanError) as exc_info:
-        machine.build_nix("config.system.build.toplevel")
+        Path(machine.select("config.system.build.toplevel"))
     assert "nixos-system-test-clan" in str(exc_info.value)

pkgs/generate-test-vars/generate_test_vars/cli.py

@@ -63,8 +63,7 @@ class TestMachine(Machine):
     def flake_dir(self) -> Path:
         return self.test_dir
 
-    @override
-    def nix(self, attr: str) -> Any:
+    def select(self, attr: str) -> Any:
         """
         Build the machine and return the path to the result
         accepts a secret store and a facts store # TODO