diff --git a/dbt_common/context.py b/dbt_common/context.py
index 35223c35..07434432 100644
--- a/dbt_common/context.py
+++ b/dbt_common/context.py
@@ -1,6 +1,5 @@
 from contextvars import ContextVar
-import os
-from typing import List, Mapping
+from typing import List, Mapping, Optional
 
 from dbt_common.constants import SECRET_ENV_PREFIX
 
@@ -8,27 +7,27 @@
 class InvocationContext:
     def __init__(self, env: Mapping[str, str]):
         self._env = env
-        self._env_secrets: List[str] = None
+        self._env_secrets: Optional[List[str]] = None
         # This class will also eventually manage the invocation_id, flags, event manager, etc.
 
     @property
     def env(self) -> Mapping[str, str]:
-        if self._env is None:
-            self._env = os.environ
-
         return self._env
 
     @property
     def env_secrets(self) -> List[str]:
-        return [v for k, v in self.env.items() if k.startswith(SECRET_ENV_PREFIX) and v.strip()]
-
+        if self._env_secrets is None:
+            self._env_secrets = [
+                v for k, v in self.env.items() if k.startswith(SECRET_ENV_PREFIX) and v.strip()
+            ]
+        return self._env_secrets
 
 
 _INVOCATION_CONTEXT_VAR: ContextVar[InvocationContext] = ContextVar("DBT_INVOCATION_CONTEXT_VAR")
 
 
-def set_invocation_context() -> None:
-    _INVOCATION_CONTEXT_VAR.set(InvocationContext())
+def set_invocation_context(env: Mapping[str, str]) -> None:
+    _INVOCATION_CONTEXT_VAR.set(InvocationContext(env))
 
 
 def get_invocation_context() -> InvocationContext:
diff --git a/tests/unit/test_invocation_context.py b/tests/unit/test_invocation_context.py
index 9653996f..f1ae4418 100644
--- a/tests/unit/test_invocation_context.py
+++ b/tests/unit/test_invocation_context.py
@@ -1,11 +1,13 @@
 from dbt_common.constants import SECRET_ENV_PREFIX
 from dbt_common.context import InvocationContext
 
+
 def test_invocation_context_env():
     test_env = {"VAR_1": "value1", "VAR_2": "value2"}
     ic = InvocationContext(env=test_env)
     assert ic.env == test_env
 
+
 def test_invocation_context_secrets():
     test_env = {
         f"{SECRET_ENV_PREFIX}_VAR_1": "secret1",
@@ -14,4 +16,4 @@ def test_invocation_context_secrets():
         f"foo{SECRET_ENV_PREFIX}": "nonsecret",
     }
     ic = InvocationContext(env=test_env)
-    assert set(ic.env_secrets) == set(["secret1", "secret2"])
\ No newline at end of file
+    assert set(ic.env_secrets) == set(["secret1", "secret2"])