Merge pull request 'machines: don't build on target machine if remote builders can be used' (#2639) from Enzime/clan-core:push-xzowvlsoytvv into main

pkgs/clan-cli/clan_cli/machines/install.py

@@ -100,7 +100,9 @@ def install_machine(opts: InstallOptions) -> None:
             ]
 
         if not machine.can_build_locally or opts.build_on_remote:
-            machine.info("Architecture mismatch. Building on remote machine")
+            machine.info(
+                f"Target machine has architecture {machine.system} which cannot be built locally or with the configured remote builders. Building on target machine"
+            )
             cmd.append("--build-on-remote")
 
         if machine.target_host.port:

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

@@ -5,6 +5,7 @@ from dataclasses import dataclass, field
 from functools import cached_property
 from pathlib import Path
 from tempfile import NamedTemporaryFile
+from time import time
 from typing import TYPE_CHECKING, Any, Literal
 
 from clan_cli.clan_uri import FlakeId
@@ -78,10 +79,32 @@ class Machine:
 
     @property
     def can_build_locally(self) -> bool:
-        # TODO: We could also use the function pkgs.stdenv.hostPlatform.canExecute
-        # but this is good enough for now.
-        output = nix_config()
-        return self.system == output["system"]
+        config = nix_config()
+        if self.system == config["system"] or self.system in config["extra-platforms"]:
+            return True
+
+        unsubstitutable_drv = json.loads(
+            run_no_stdout(
+                nix_eval(
+                    [
+                        "--impure",
+                        "--expr",
+                        f'((builtins.getFlake "{self.flake}").inputs.nixpkgs.legacyPackages.{self.system}.runCommandNoCC "clan-can-build-{int(time())}" {{ }} "touch $out").drvPath',
+                    ]
+                ),
+                opts=RunOpts(prefix=self.name),
+            ).stdout.strip()
+        )
+
+        try:
+            run_no_stdout(
+                nix_build([f"{unsubstitutable_drv}^*"]), opts=RunOpts(prefix=self.name)
+            )
+        except Exception as e:
+            self.debug("failed to build test derivation", exc_info=e)
+            return False
+        else:
+            return True
 
     @property
     def deployment(self) -> dict:

pyproject.toml

@@ -46,7 +46,6 @@ lint.select = [
 ]
 lint.ignore = [
   "A003",
-  "ANN101",
   "ANN401",
   "TRY400",
   "E402",