Fix a crash from astroid.InferenceError raised on copy.copy

Closes #4891

3 files changed, 29 insertions, 3 deletions

diff --git a/ChangeLog b/ChangeLog
index 49fc5d968..832f4b6a7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -22,6 +22,12 @@ Release date: TBA
 
   Closes #4886
 
+* Fix a crash in the checker raising ``shallow-copy-environ`` when failing to infer
+  on ``copy.copy``
+
+  Closes #4896
+
+
 
 What's New in Pylint 2.10.1?
 ============================
diff --git a/pylint/checkers/stdlib.py b/pylint/checkers/stdlib.py
index cffc8a4d5..b7a6e031b 100644
--- a/pylint/checkers/stdlib.py
+++ b/pylint/checkers/stdlib.py
@@ -483,9 +483,13 @@ class StdlibChecker(DeprecatedMixin, BaseChecker):
         if "check" not in kwargs:
             self.add_message("subprocess-run-check", node=node)
 
-    def _check_shallow_copy_environ(self, node):
+    def _check_shallow_copy_environ(self, node: nodes.Call) -> None:
         arg = utils.get_argument_from_call(node, position=0)
-        for inferred in arg.inferred():
+        try:
+            inferred_args = arg.inferred()
+        except astroid.InferenceError:
+            return
+        for inferred in inferred_args:
             if inferred.qname() == OS_ENVIRON:
                 self.add_message("shallow-copy-environ", node=node)
                 break
@@ -505,7 +509,7 @@ class StdlibChecker(DeprecatedMixin, BaseChecker):
         "unspecified-encoding",
         "forgotten-debug-statement",
     )
-    def visit_call(self, node):
+    def visit_call(self, node: nodes.Call) -> None:
         """Visit a Call node."""
         self.check_deprecated_class_in_call(node)
         for inferred in utils.infer_all(node.func):
diff --git a/tests/functional/r/regression/regression_4891.py b/tests/functional/r/regression/regression_4891.py
new file mode 100644
index 000000000..34945e812
--- /dev/null
+++ b/tests/functional/r/regression/regression_4891.py
@@ -0,0 +1,16 @@
+# pylint: disable=missing-module-docstring
+# pylint: disable=too-few-public-methods
+import copy
+
+class MyData:
+    '''
+    class docstring
+    '''
+    def __init__(self):
+        self.data = {}
+
+    def process(self):
+        '''
+        another method is responsible for putting "static_key"
+        '''
+        copy.copy(self.data['static_key'])