Show a clearer message when Rosetta is not available

README.md

@@ -79,13 +79,20 @@ Feel free to stop by our [Slack channel](https://empirehacking.slack.com/) for h
 ## FAQ
 
 ### OSError: [Errno 86] Bad CPU type in executable
-`solc` requires Rosetta to be installed. To see whether you have Rosetta installed on your mac, run
-```
+
+On newer `solc-select` versions, this might show as `solc binaries for macOS are
+Intel-only. Please install Rosetta on your Mac to continue.`
+
+`solc` requires Rosetta to be installed. To see whether you have Rosetta
+installed on your Mac, run
+
+```bash
 pgrep -q oahd && echo Rosetta is installed || echo Rosetta is NOT installed
 ```
 
 If it is not installed, it can be installed with the command
-```
+
+```bash
 /usr/sbin/softwareupdate --install-rosetta --agree-to-license
 ```
 

solc_select/__main__.py

@@ -16,6 +16,7 @@
     switch_global_version,
     current_version,
     installed_versions,
+    halt_incompatible_system,
     halt_old_architecture,
     upgrade_architecture,
 )
@@ -88,6 +89,7 @@ def solc() -> None:
         (version, _) = res
         path = ARTIFACTS_DIR.joinpath(f"solc-{version}", f"solc-{version}")
         halt_old_architecture(path)
+        halt_incompatible_system()
         try:
             subprocess.run(
                 [str(path)] + sys.argv[1:],

solc_select/solc_select.py

@@ -20,6 +20,7 @@
     CRYTIC_SOLC_ARTIFACTS,
     CRYTIC_SOLC_JSON,
 )
+from .utils import mac_can_run_intel_binaries
 
 Path.mkdir(ARTIFACTS_DIR, parents=True, exist_ok=True)
 
@@ -31,6 +32,14 @@ def halt_old_architecture(path: Path) -> None:
         )
 
 
+def halt_incompatible_system() -> None:
+    if soliditylang_platform() == MACOSX_AMD64 and not mac_can_run_intel_binaries():
+        raise argparse.ArgumentTypeError(
+            "solc binaries for macOS are Intel-only. Please install Rosetta on your Mac to continue. Refer to the solc-select README for instructions."
+        )
+    # TODO: check for Linux aarch64 (e.g. RPi), presence of QEMU+binfmt
+
+
 def upgrade_architecture() -> None:
     currently_installed = installed_versions()
     if len(currently_installed) > 0:

solc_select/utils.py

@@ -0,0 +1,15 @@
+import platform
+import subprocess
+import sys
+
+
+def mac_can_run_intel_binaries() -> bool:
+    """Check if the Mac is Intel or M1 with available Rosetta. Will throw an exception if run on non-macOS."""
+    assert sys.platform == "darwin"
+    if platform.machine() == "arm64":
+        # M1/M2 Mac
+        result = subprocess.run(["/usr/bin/pgrep", "-q", "oahd"], capture_output=True, check=False)
+        return result.returncode == 0
+
+    # Intel Mac
+    return True