Fix misleading error message when SSH installation fails

incant/provisioners/ssh_server.py

@@ -90,11 +90,12 @@ def _install_ssh_server(self, name: str) -> bool:
         for pm in package_managers:
             try:
                 self.incus.exec(name, ["sh", "-c", pm["check_cmd"]], capture_output=True)
-                for cmd in pm["install_cmds"]:
-                    self.incus.exec(name, ["sh", "-c", cmd], capture_output=False)
-                return True  # Installed
             except IncusCommandError:
                 continue  # Try next package manager
+
+            for cmd in pm["install_cmds"]:
+                self.incus.exec(name, ["sh", "-c", cmd], capture_output=False)
+            return True  # Installed
         return False  # Not installed
 
     def _get_authorized_keys_content(self, ssh_config: Union[dict, bool]) -> str:

tests/test_ssh_provisioner.py

@@ -0,0 +1,52 @@
+from unittest.mock import Mock, call
+import pytest
+from incant.provisioners.ssh_server import SSHServer
+from incant.exceptions import IncusCommandError
+from incant.reporter import Reporter
+
+
+@pytest.fixture
+def mock_incus_cli():
+    return Mock()
+
+
+@pytest.fixture
+def mock_reporter():
+    return Mock(spec=Reporter)
+
+
+def test_ssh_provisioner_misleading_error(mock_incus_cli, mock_reporter):
+    # Setup
+    ssh_provisioner = SSHServer(mock_incus_cli, mock_reporter)
+    instance_name = "test-vm"
+
+    # Mock behavior:
+    # 1. check apt-get -> Success
+    # 2. install ssh (apt-get) -> Fail (Network error)
+    # 3. check dnf -> Fail (Not found)
+    # 4. check pacman -> Fail (Not found)
+
+    def side_effect(name, cmd, **kwargs):
+        cmd_str = " ".join(cmd)
+        if "command -v apt-get" in cmd_str:
+            return ""  # Success
+        if "apt-get update" in cmd_str:
+            raise IncusCommandError(
+                "Temporary failure resolving 'deb.debian.org'",
+                stderr="Temporary failure resolving 'deb.debian.org'",
+            )
+        if "command -v dnf" in cmd_str:
+            raise IncusCommandError("dnf not found")
+        if "command -v pacman" in cmd_str:
+            raise IncusCommandError("pacman not found")
+        return ""
+
+    mock_incus_cli.exec.side_effect = side_effect
+
+    # Run
+    # This should raise IncusCommandError because apt-get was found
+    # but the installation failed.
+    with pytest.raises(IncusCommandError) as excinfo:
+        ssh_provisioner._install_ssh_server(instance_name)
+
+    assert "Temporary failure resolving 'deb.debian.org'" in str(excinfo.value)