We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Dual distro support broke "securedrop-admin verify"
## Description

When adding support for Focal to the configuration tests in #5529, a check of the `MOLECULE_SCENARIO_NAME` environment variable broke `securedrop-admin verify`, where it's not set.

## Steps to Reproduce

On an admin workstation:
- Run `securedrop-admin setup -t`
- Run `securedrop-admin verify`

## Expected Behavior

That the configuration tests would run.

## Actual Behavior

You get an error [here](https://github.com/freedomofpress/securedrop/blob/76d133a7e5962f8d904e507d93e6a61575358eeb/molecule/testinfra/conftest.py#L31) saying `'NoneType' object has no attribute 'endswith'`. 

## Comments

Should probably check if it's `None` or just add `""` as the default in the `os.environ.get` call.

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `molecule/testinfra/conftest.py`
Content:
```
1 """
2 Configuration for TestInfra test suite for SecureDrop.
3 Handles importing host-specific test vars, so test functions
4 can be reused across multiple hosts, with varied targets.
5 
6 Vars should be placed in `testinfra/vars/<hostname>.yml`.
7 """
8 
9 import io
10 import os
11 import yaml
12 import testutils
13 
14 # The config tests target staging by default. It's possible to override
15 # for e.g. prod, but the associated vars files are not yet ported.
16 target_host = os.environ.get('SECUREDROP_TESTINFRA_TARGET_HOST', 'staging')
17 
18 
19 def securedrop_import_testinfra_vars(hostname, with_header=False):
20     """
21     Import vars from a YAML file to populate tests with host-specific
22     values used in checks. For instance, the SecureDrop docroot will
23     be under /vagrant in development, but /var/www/securedrop in staging.
24 
25     Vars must be stored in `testinfra/vars/<hostname>.yml`.
26     """
27     filepath = os.path.join(os.path.dirname(__file__), "vars", hostname+".yml")
28     with io.open(filepath, 'r') as f:
29         hostvars = yaml.safe_load(f)
30 
31     if os.environ.get("MOLECULE_SCENARIO_NAME").endswith("focal"):
32         hostvars['securedrop_venv_site_packages'] = hostvars["securedrop_venv_site_packages"].format("3.8")  # noqa: E501
33         hostvars['python_version'] = "3.8"
34     else:
35         hostvars['securedrop_venv_site_packages'] = hostvars["securedrop_venv_site_packages"].format("3.5")  # noqa: E501
36         hostvars['python_version'] = "3.5"
37 
38     if with_header:
39         hostvars = dict(securedrop_test_vars=hostvars)
40 
41     return hostvars
42 
43 
44 def lookup_molecule_info():
45     """
46     Molecule automatically writes YAML files documenting dynamic host info
47     such as remote IPs. Read that file and pass back the config dict.
48     """
49     molecule_instance_config_path = os.path.abspath(
50             os.environ['MOLECULE_INSTANCE_CONFIG'])
51     with open(molecule_instance_config_path, 'r') as f:
52         molecule_instance_config = yaml.safe_load(f)
53     return molecule_instance_config
54 
55 
56 class Myvalues:
57     def __init__(self):
58         pass
59 
60 
61 value = securedrop_import_testinfra_vars(target_host)
62 res = Myvalues()
63 for key, value in value.items():
64     setattr(res, key, value)
65 testutils.securedrop_test_vars = res
66
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/molecule/testinfra/conftest.py b/molecule/testinfra/conftest.py
--- a/molecule/testinfra/conftest.py
+++ b/molecule/testinfra/conftest.py
@@ -28,7 +28,16 @@
     with io.open(filepath, 'r') as f:
         hostvars = yaml.safe_load(f)
 
-    if os.environ.get("MOLECULE_SCENARIO_NAME").endswith("focal"):
+    # Testing against both Focal and Xenial must be supported for now in both
+    # staging scenarios, and in prod via `USE_FOCAL=1 ./securedrop-admin verify`
+    testing_focal = False
+    scenario_env = "MOLECULE_SCENARIO_NAME"
+    if scenario_env in os.environ and os.environ.get(scenario_env).endswith("focal"):
+        testing_focal = True
+    if "USE_FOCAL" in os.environ:
+        testing_focal = True
+
+    if testing_focal:
         hostvars['securedrop_venv_site_packages'] = hostvars["securedrop_venv_site_packages"].format("3.8")  # noqa: E501
         hostvars['python_version'] = "3.8"
     else:

{"golden_diff": "diff --git a/molecule/testinfra/conftest.py b/molecule/testinfra/conftest.py\n--- a/molecule/testinfra/conftest.py\n+++ b/molecule/testinfra/conftest.py\n@@ -28,7 +28,16 @@\n     with io.open(filepath, 'r') as f:\n         hostvars = yaml.safe_load(f)\n \n-    if os.environ.get(\"MOLECULE_SCENARIO_NAME\").endswith(\"focal\"):\n+    # Testing against both Focal and Xenial must be supported for now in both\n+    # staging scenarios, and in prod via `USE_FOCAL=1 ./securedrop-admin verify`\n+    testing_focal = False\n+    scenario_env = \"MOLECULE_SCENARIO_NAME\"\n+    if scenario_env in os.environ and os.environ.get(scenario_env).endswith(\"focal\"):\n+        testing_focal = True\n+    if \"USE_FOCAL\" in os.environ:\n+        testing_focal = True\n+\n+    if testing_focal:\n         hostvars['securedrop_venv_site_packages'] = hostvars[\"securedrop_venv_site_packages\"].format(\"3.8\")  # noqa: E501\n         hostvars['python_version'] = \"3.8\"\n     else:\n", "issue": "Dual distro support broke \"securedrop-admin verify\"\n## Description\r\n\r\nWhen adding support for Focal to the configuration tests in #5529, a check of the `MOLECULE_SCENARIO_NAME` environment variable broke `securedrop-admin verify`, where it's not set.\r\n\r\n## Steps to Reproduce\r\n\r\nOn an admin workstation:\r\n- Run `securedrop-admin setup -t`\r\n- Run `securedrop-admin verify`\r\n\r\n## Expected Behavior\r\n\r\nThat the configuration tests would run.\r\n\r\n## Actual Behavior\r\n\r\nYou get an error [here](https://github.com/freedomofpress/securedrop/blob/76d133a7e5962f8d904e507d93e6a61575358eeb/molecule/testinfra/conftest.py#L31) saying `'NoneType' object has no attribute 'endswith'`. \r\n\r\n## Comments\r\n\r\nShould probably check if it's `None` or just add `\"\"` as the default in the `os.environ.get` call.\n", "before_files": [{"content": "\"\"\"\nConfiguration for TestInfra test suite for SecureDrop.\nHandles importing host-specific test vars, so test functions\ncan be reused across multiple hosts, with varied targets.\n\nVars should be placed in `testinfra/vars/<hostname>.yml`.\n\"\"\"\n\nimport io\nimport os\nimport yaml\nimport testutils\n\n# The config tests target staging by default. It's possible to override\n# for e.g. prod, but the associated vars files are not yet ported.\ntarget_host = os.environ.get('SECUREDROP_TESTINFRA_TARGET_HOST', 'staging')\n\n\ndef securedrop_import_testinfra_vars(hostname, with_header=False):\n    \"\"\"\n    Import vars from a YAML file to populate tests with host-specific\n    values used in checks. For instance, the SecureDrop docroot will\n    be under /vagrant in development, but /var/www/securedrop in staging.\n\n    Vars must be stored in `testinfra/vars/<hostname>.yml`.\n    \"\"\"\n    filepath = os.path.join(os.path.dirname(__file__), \"vars\", hostname+\".yml\")\n    with io.open(filepath, 'r') as f:\n        hostvars = yaml.safe_load(f)\n\n    if os.environ.get(\"MOLECULE_SCENARIO_NAME\").endswith(\"focal\"):\n        hostvars['securedrop_venv_site_packages'] = hostvars[\"securedrop_venv_site_packages\"].format(\"3.8\")  # noqa: E501\n        hostvars['python_version'] = \"3.8\"\n    else:\n        hostvars['securedrop_venv_site_packages'] = hostvars[\"securedrop_venv_site_packages\"].format(\"3.5\")  # noqa: E501\n        hostvars['python_version'] = \"3.5\"\n\n    if with_header:\n        hostvars = dict(securedrop_test_vars=hostvars)\n\n    return hostvars\n\n\ndef lookup_molecule_info():\n    \"\"\"\n    Molecule automatically writes YAML files documenting dynamic host info\n    such as remote IPs. Read that file and pass back the config dict.\n    \"\"\"\n    molecule_instance_config_path = os.path.abspath(\n            os.environ['MOLECULE_INSTANCE_CONFIG'])\n    with open(molecule_instance_config_path, 'r') as f:\n        molecule_instance_config = yaml.safe_load(f)\n    return molecule_instance_config\n\n\nclass Myvalues:\n    def __init__(self):\n        pass\n\n\nvalue = securedrop_import_testinfra_vars(target_host)\nres = Myvalues()\nfor key, value in value.items():\n    setattr(res, key, value)\ntestutils.securedrop_test_vars = res\n", "path": "molecule/testinfra/conftest.py"}], "after_files": [{"content": "\"\"\"\nConfiguration for TestInfra test suite for SecureDrop.\nHandles importing host-specific test vars, so test functions\ncan be reused across multiple hosts, with varied targets.\n\nVars should be placed in `testinfra/vars/<hostname>.yml`.\n\"\"\"\n\nimport io\nimport os\nimport yaml\nimport testutils\n\n# The config tests target staging by default. It's possible to override\n# for e.g. prod, but the associated vars files are not yet ported.\ntarget_host = os.environ.get('SECUREDROP_TESTINFRA_TARGET_HOST', 'staging')\n\n\ndef securedrop_import_testinfra_vars(hostname, with_header=False):\n    \"\"\"\n    Import vars from a YAML file to populate tests with host-specific\n    values used in checks. For instance, the SecureDrop docroot will\n    be under /vagrant in development, but /var/www/securedrop in staging.\n\n    Vars must be stored in `testinfra/vars/<hostname>.yml`.\n    \"\"\"\n    filepath = os.path.join(os.path.dirname(__file__), \"vars\", hostname+\".yml\")\n    with io.open(filepath, 'r') as f:\n        hostvars = yaml.safe_load(f)\n\n    # Testing against both Focal and Xenial must be supported for now in both\n    # staging scenarios, and in prod via `USE_FOCAL=1 ./securedrop-admin verify`\n    testing_focal = False\n    scenario_env = \"MOLECULE_SCENARIO_NAME\"\n    if scenario_env in os.environ and os.environ.get(scenario_env).endswith(\"focal\"):\n        testing_focal = True\n    if \"USE_FOCAL\" in os.environ:\n        testing_focal = True\n\n    if testing_focal:\n        hostvars['securedrop_venv_site_packages'] = hostvars[\"securedrop_venv_site_packages\"].format(\"3.8\")  # noqa: E501\n        hostvars['python_version'] = \"3.8\"\n    else:\n        hostvars['securedrop_venv_site_packages'] = hostvars[\"securedrop_venv_site_packages\"].format(\"3.5\")  # noqa: E501\n        hostvars['python_version'] = \"3.5\"\n\n    if with_header:\n        hostvars = dict(securedrop_test_vars=hostvars)\n\n    return hostvars\n\n\ndef lookup_molecule_info():\n    \"\"\"\n    Molecule automatically writes YAML files documenting dynamic host info\n    such as remote IPs. Read that file and pass back the config dict.\n    \"\"\"\n    molecule_instance_config_path = os.path.abspath(\n            os.environ['MOLECULE_INSTANCE_CONFIG'])\n    with open(molecule_instance_config_path, 'r') as f:\n        molecule_instance_config = yaml.safe_load(f)\n    return molecule_instance_config\n\n\nclass Myvalues:\n    def __init__(self):\n        pass\n\n\nvalue = securedrop_import_testinfra_vars(target_host)\nres = Myvalues()\nfor key, value in value.items():\n    setattr(res, key, value)\ntestutils.securedrop_test_vars = res\n", "path": "molecule/testinfra/conftest.py"}]}