Remove jinja2 checks since it is already an explicit dependency

conda_build/exceptions.py

@@ -4,6 +4,8 @@
 
 from conda import CondaError
 
+from .deprecations import deprecated
+
 SEPARATOR = "-" * 70
 
 indent = lambda s: textwrap.fill(textwrap.dedent(s))
@@ -44,6 +46,7 @@ def indented_exception(self):
         return f"Error Message:\n--> {indent(orig)}\n\n"
 
 
+@deprecated("24.11", "25.1")
 class UnableToParseMissingJinja2(UnableToParse):
     def error_body(self):
         return "\n".join(

conda_build/metadata.py

@@ -15,6 +15,7 @@
 from os.path import isdir, isfile, join
 from typing import TYPE_CHECKING, NamedTuple, overload
 
+import jinja2
 import yaml
 from bs4 import UnicodeDammit
 from conda.base.context import locate_prefix_by_name
@@ -30,7 +31,6 @@
     DependencyNeedsBuildingError,
     RecipeError,
     UnableToParse,
-    UnableToParseMissingJinja2,
 )
 from .features import feature_list
 from .license_family import ensure_valid_license_family
@@ -358,13 +358,6 @@ def yamlize(data):
     try:
         return yaml.load(data, Loader=StringifyNumbersLoader)
     except yaml.error.YAMLError as e:
-        if "{{" in data:
-            try:
-                import jinja2
-
-                jinja2  # Avoid pyflakes failure: 'jinja2' imported but unused
-            except ImportError:
-                raise UnableToParseMissingJinja2(original=e)
         print("Problematic recipe:", file=sys.stderr)
         print(data, file=sys.stderr)
         raise UnableToParse(original=e)
@@ -1918,17 +1911,6 @@ def _get_contents(
         permit_undefined_jinja: If True, *any* use of undefined jinja variables will
                                 evaluate to an emtpy string, without emitting an error.
         """
-        try:
-            import jinja2
-        except ImportError:
-            print("There was an error importing jinja2.", file=sys.stderr)
-            print(
-                "Please run `conda install jinja2` to enable jinja template support",
-                file=sys.stderr,
-            )  # noqa
-            with open(self.meta_path) as fd:
-                return fd.read()
-
         from .jinja_context import (
             FilteredLoader,
             UndefinedNeverFail,

news/5497-deprecate-UnableToParseMissingJinja2

@@ -0,0 +1,19 @@
+### Enhancements
+
+* <news item>
+
+### Bug fixes
+
+* <news item>
+
+### Deprecations
+
+* Deprecate `conda_build.exceptions.UnableToParseMissingJinja2`. (#5497)
+
+### Docs
+
+* <news item>
+
+### Other
+
+* <news item>

tests/test_exceptions.py

@@ -0,0 +1,21 @@
+# Copyright (C) 2014 Anaconda, Inc
+# SPDX-License-Identifier: BSD-3-Clause
+from __future__ import annotations
+
+from contextlib import nullcontext
+
+import pytest
+
+from conda_build import exceptions
+
+
+@pytest.mark.parametrize(
+    "function,raises",
+    [
+        ("UnableToParseMissingJinja2", TypeError),
+    ],
+)
+def test_deprecations(function: str, raises: type[Exception] | None) -> None:
+    raises_context = pytest.raises(raises) if raises else nullcontext()
+    with pytest.deprecated_call(), raises_context:
+        getattr(exceptions, function)()