improve error messages in ConanApi init failures (conan-io#14735)

* improve error messages in ConanApi init failures

* fix

conans/client/cache/cache.py

@@ -48,9 +48,12 @@ def __init__(self, cache_folder):
         self._store_folder = self.new_config.get("core.cache:storage_path") or \
                              os.path.join(self.cache_folder, "p")
 
-        mkdir(self._store_folder)
-        db_filename = os.path.join(self._store_folder, 'cache.sqlite3')
-        self._data_cache = DataCache(self._store_folder, db_filename)
+        try:
+            mkdir(self._store_folder)
+            db_filename = os.path.join(self._store_folder, 'cache.sqlite3')
+            self._data_cache = DataCache(self._store_folder, db_filename)
+        except Exception as e:
+            raise ConanException(f"Couldn't initialize storage in {self._store_folder}: {e}")
 
     @property
     def temp_folder(self):

conans/test/integration/configuration/conf/test_conf.py

@@ -140,10 +140,9 @@ def test_new_config_file_required_version():
         core:required_conan_version=>=2.0
         """)
     save(client.cache.new_config_path, conf)
-    with pytest.raises(ConanException) as excinfo:
-        client.run("install .")
+    client.run("install .", assert_error=True)
     assert ("Current Conan version (1.26.0) does not satisfy the defined one (>=2.0)"
-            in str(excinfo.value))
+            in client.out)
 
 
 def test_composition_conan_conf_overwritten_by_cli_arg(client):

conans/test/integration/configuration/required_version_test.py

@@ -17,10 +17,9 @@ def test_wrong_version(self):
         client = TestClient()
         client.save({"global.conf": f"core:required_conan_version={required_version}"},
                     path=client.cache.cache_folder)
-        with self.assertRaises(ConanException) as error:
-            client.run("help")
+        client.run("help", assert_error=True)
         self.assertIn("Current Conan version (1.26.0) does not satisfy the defined "
-                      "one ({})".format(required_version), str(error.exception))
+                      "one ({})".format(required_version), client.out)
 
     @mock.patch("conans.client.conf.required_version.client_version", "1.22.0")
     def test_exact_version(self):

conans/test/integration/ui/exit_with_code_test.py

@@ -2,6 +2,7 @@
 
 from conans.paths import CONANFILE
 from conans.test.utils.tools import TestClient
+from conans.util.files import save
 
 
 class ExitWithCodeTest(unittest.TestCase):
@@ -27,3 +28,10 @@ def build(self):
         error_code = client.run("build .", assert_error=True)
         self.assertEqual(error_code, 34)
         self.assertIn("Exiting with code: 34", client.out)
+
+
+def test_wrong_home_error():
+    client = TestClient()
+    save(client.cache.new_config_path, "core.cache:storage_path=//")
+    client.run("--version")
+    assert "Error in Conan initialization: Couldn't initialize storage in" in client.out

conans/test/utils/tools.py

@@ -24,15 +24,15 @@
 from requests.exceptions import HTTPError
 from webtest.app import TestApp
 
-from conan.cli.exit_codes import SUCCESS
+from conan.cli.exit_codes import SUCCESS, ERROR_GENERAL
 from conan.internal.cache.cache import PackageLayout, RecipeLayout
 from conans import REVISIONS
 from conan.api.conan_api import ConanAPI
 from conan.api.model import Remote
 from conan.cli.cli import Cli
 from conans.client.cache.cache import ClientCache
 from conans.util.env import environment_update
-from conans.errors import NotFoundException
+from conans.errors import NotFoundException, ConanException
 from conans.model.manifest import FileTreeManifest
 from conans.model.package_ref import PkgReference
 from conans.model.profile import Profile
@@ -489,8 +489,12 @@ def _run_cli(self, command_line, assert_error=False):
 
         args = shlex.split(command_line)
 
-        self.api = ConanAPI(cache_folder=self.cache_folder)
-        command = Cli(self.api)
+        try:
+            self.api = ConanAPI(cache_folder=self.cache_folder)
+            command = Cli(self.api)
+        except ConanException as e:
+            sys.stderr.write("Error in Conan initialization: {}".format(e))
+            return ERROR_GENERAL
 
         error = SUCCESS
         trace = None