Smartly guess the channel considering the architecture

README.md

@@ -19,6 +19,9 @@ usage: hydra-check [options] PACKAGES...
 $ hydra-check hello
 Build Status for nixpkgs.hello.x86_64-linux on jobset nixos/trunk-combined
 ✔ hello-2.10 from 2020-03-14 - https://hydra.nixos.org/build/114752982
+$ hydra-check hello --arch x86_64-darwin
+Build Status for hello.x86_64-darwin on jobset nixpkgs/trunk
+✔ hello-2.12.1 from 2023-09-28 - https://hydra.nixos.org/build/236635446
 
 
 $ hydra-check hello python --channel 19.03

src/hydra_check/arguments.py

@@ -7,8 +7,8 @@ def process_args() -> argparse.Namespace:
             formatter_class=argparse.RawDescriptionHelpFormatter,
             epilog=textwrap.dedent('''\
                 Other channels can be:
-                    unstable  - alias for nixos/trunk-combined (Default)
-                    master    - alias for nixpkgs/trunk
+                    unstable  - alias for nixos/trunk-combined (Default for Linux architectures)
+                    master    - alias for nixpkgs/trunk (Default for Darwin architectures)
                     staging   - alias for nixos/staging
                     19.03     - alias for nixos/release-19.03
                     19.09     - alias for nixos/release-19.09
@@ -53,6 +53,7 @@ def process_args() -> argparse.Namespace:
     )
     parser.add_argument(
         "--channel",
+        # Sort of changes to "master" when arch is darwin
         default="unstable",
         help="Channel to check packages for",
     )

src/hydra_check/cli.py

@@ -15,13 +15,16 @@
 
 
 # guess functions are intended to be fast without external queries
-def guess_jobset(channel: str) -> str:
+def guess_jobset(channel: str, arch: str) -> str:
     # TODO guess the latest stable channel
     match channel:
         case "master":
             return "nixpkgs/trunk"
         case "unstable":
-            return "nixos/trunk-combined"
+            if arch.endswith("darwin"):
+                return "nixpkgs/trunk"
+            else:
+                return "nixos/trunk-combined"
         case "staging":
             return "nixos/staging"
         case _:
@@ -146,7 +149,7 @@ def main() -> None:
     channel = args.channel
     packages: list[str] = args.PACKAGES
     only_url = args.url
-    jobset = args.jobset or guess_jobset(channel)
+    jobset = args.jobset or guess_jobset(channel, args.arch)
     is_channel = jobset.startswith("nixos/")
     as_json = args.json
     all_builds = {}