diff --git a/pre_commit/commands/run.py b/pre_commit/commands/run.py
index c70eff0..a16d8fe 100644
--- a/pre_commit/commands/run.py
+++ b/pre_commit/commands/run.py
@@ -67,6 +67,15 @@ def _run_single_hook(filenames, hook, repo, args, skips, cols):
     filenames = _filter_by_include_exclude(filenames, include, exclude)
     types, exclude_types = hook['types'], hook['exclude_types']
     filenames = _filter_by_types(filenames, types, exclude_types)
+
+    if hook['language'] == 'pcre':
+        logger.warning(
+            '`{}` (from {}) uses the deprecated pcre language.\n'
+            'The pcre language is scheduled for removal in pre-commit 2.x.\n'
+            'The pygrep language is a more portable (and usually drop-in) '
+            'replacement.'.format(hook['id'], repo.repo_config['repo']),
+        )
+
     if hook['id'] in skips:
         output.write(get_hook_message(
             _hook_msg_start(hook, args.verbose),

Deprecate `pcre` language
Now that pygrep (#630) is a much more portable alternative, pcre is unnecessary and should be deprecated.

A deprecation warning should be issued when loading a configuration containing `language: pcre` and should point the consumer in the right direction to correcting it (either by suggesting a pull request, or by indicating they should modify their `local` configuration).

The `pcre` language will likely be removed in `pre-commit==2.0.0`
diff --git a/tests/commands/run_test.py b/tests/commands/run_test.py
index 97c82c2..cbf4e98 100644
--- a/tests/commands/run_test.py
+++ b/tests/commands/run_test.py
@@ -529,7 +529,7 @@ def test_push_hook(cap_out, repo_with_passing_hook, mock_out_store_directory):
                     ('id', 'do_not_commit'),
                     ('name', 'hook 2'),
                     ('entry', 'DO NOT COMMIT'),
-                    ('language', 'pcre'),
+                    ('language', 'pygrep'),
                     ('types', ['text']),
                     ('stages', ['push']),
                 )),
@@ -592,7 +592,7 @@ def test_local_hook_passes(
                     ('id', 'do_not_commit'),
                     ('name', 'Block if "DO NOT COMMIT" is found'),
                     ('entry', 'DO NOT COMMIT'),
-                    ('language', 'pcre'),
+                    ('language', 'pygrep'),
                     ('files', '^(.*)$'),
                 )),
             ),
@@ -645,6 +645,35 @@ def test_local_hook_fails(
     )
 
 
+def test_pcre_deprecation_warning(
+        cap_out, repo_with_passing_hook, mock_out_store_directory,
+):
+    config = OrderedDict((
+        ('repo', 'local'),
+        (
+            'hooks', [OrderedDict((
+                ('id', 'pcre-hook'),
+                ('name', 'pcre-hook'),
+                ('language', 'pcre'),
+                ('entry', '.'),
+            ))],
+        ),
+    ))
+    add_config_to_repo(repo_with_passing_hook, config)
+
+    _test_run(
+        cap_out,
+        repo_with_passing_hook,
+        opts={},
+        expected_outputs=[
+            b'[WARNING] `pcre-hook` (from local) uses the deprecated '
+            b'pcre language.',
+        ],
+        expected_ret=0,
+        stage=False,
+    )
+
+
 def test_meta_hook_passes(
         cap_out, repo_with_passing_hook, mock_out_store_directory,
 ):

pip install -e .
parse_log_pytest
requirements.txt
3.6
requirements-dev.txt
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
aspy.yaml==1.3.0
attrs==22.2.0
cached-property==1.5.2
certifi==2021.5.30
coverage==6.2
distlib==0.3.9
filelock==3.4.1
flake8==5.0.4
identify==2.4.4
importlib-metadata==4.8.3
importlib-resources==5.4.0
iniconfig==1.1.1
mccabe==0.7.0
mock==5.2.0
nodeenv==1.6.0
packaging==21.3
platformdirs==2.4.0
pluggy==1.0.0
-e git+https://github.com/pre-commit/pre-commit.git@65f60e25930a4979a4571e41f320b81f622b2556#egg=pre_commit
py==1.11.0
pycodestyle==2.9.1
pyflakes==2.5.0
pyparsing==3.1.4
pytest==7.0.1
pytest-env==0.6.2
PyYAML==6.0.1
six==1.17.0
tomli==1.2.3
typing_extensions==4.1.1
virtualenv==20.17.1
zipp==3.6.0

name: pre-commit
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2021.5.30=py36h06a4308_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.3=he6710b0_2
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - pip=21.2.2=py36h06a4308_0
  - python=3.6.13=h12debd9_1
  - readline=8.2=h5eee18b_0
  - setuptools=58.0.4=py36h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - wheel=0.37.1=pyhd3eb1b0_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - aspy-yaml==1.3.0
      - attrs==22.2.0
      - cached-property==1.5.2
      - coverage==6.2
      - distlib==0.3.9
      - filelock==3.4.1
      - flake8==5.0.4
      - identify==2.4.4
      - importlib-metadata==4.8.3
      - importlib-resources==5.4.0
      - iniconfig==1.1.1
      - mccabe==0.7.0
      - mock==5.2.0
      - nodeenv==1.6.0
      - packaging==21.3
      - platformdirs==2.4.0
      - pluggy==1.0.0
      - py==1.11.0
      - pycodestyle==2.9.1
      - pyflakes==2.5.0
      - pyparsing==3.1.4
      - pytest==7.0.1
      - pytest-env==0.6.2
      - pyyaml==6.0.1
      - six==1.17.0
      - tomli==1.2.3
      - typing-extensions==4.1.1
      - virtualenv==20.17.1
      - zipp==3.6.0
prefix: /opt/conda/envs/pre-commit

tests/commands/run_test.py::test_pcre_deprecation_warning
tests/commands/run_test.py::test_hook_install_failure
tests/commands/run_test.py::test_run_all_hooks_failing tests/commands/run_test.py::test_arbitrary_bytes_hook tests/commands/run_test.py::test_hook_that_modifies_but_returns_zero tests/commands/run_test.py::test_types_hook_repository tests/commands/run_test.py::test_exclude_types_hook_repository tests/commands/run_test.py::test_global_exclude tests/commands/run_test.py::test_show_diff_on_failure tests/commands/run_test.py::test_run[options0-outputs0-0-True] tests/commands/run_test.py::test_run[options1-outputs1-0-True] tests/commands/run_test.py::test_run[options2-outputs2-0-True] tests/commands/run_test.py::test_run[options3-outputs3-1-True] tests/commands/run_test.py::test_run[options4-outputs4-0-True] tests/commands/run_test.py::test_run[options5-outputs5-0-True] tests/commands/run_test.py::test_run[options6-outputs6-0-False] tests/commands/run_test.py::test_run_output_logfile tests/commands/run_test.py::test_always_run tests/commands/run_test.py::test_always_run_alt_config tests/commands/run_test.py::test_origin_source_error_msg[master-master-False] tests/commands/run_test.py::test_origin_source_error_msg[master--True] tests/commands/run_test.py::test_origin_source_error_msg[-master-True] tests/commands/run_test.py::test_has_unmerged_paths tests/commands/run_test.py::test_merge_conflict tests/commands/run_test.py::test_merge_conflict_modified tests/commands/run_test.py::test_merge_conflict_resolved tests/commands/run_test.py::test_compute_cols[hooks0-True-80] tests/commands/run_test.py::test_compute_cols[hooks1-False-81] tests/commands/run_test.py::test_compute_cols[hooks2-True-85] tests/commands/run_test.py::test_compute_cols[hooks3-False-82] tests/commands/run_test.py::test_get_skips[environ0-expected_output0] tests/commands/run_test.py::test_get_skips[environ1-expected_output1] tests/commands/run_test.py::test_get_skips[environ2-expected_output2] tests/commands/run_test.py::test_get_skips[environ3-expected_output3] tests/commands/run_test.py::test_get_skips[environ4-expected_output4] tests/commands/run_test.py::test_get_skips[environ5-expected_output5] tests/commands/run_test.py::test_get_skips[environ6-expected_output6] tests/commands/run_test.py::test_skip_hook tests/commands/run_test.py::test_hook_id_not_in_non_verbose_output tests/commands/run_test.py::test_hook_id_in_verbose_output tests/commands/run_test.py::test_multiple_hooks_same_id tests/commands/run_test.py::test_non_ascii_hook_id tests/commands/run_test.py::test_stdout_write_bug_py26 tests/commands/run_test.py::test_lots_of_files tests/commands/run_test.py::test_push_hook tests/commands/run_test.py::test_commit_msg_hook tests/commands/run_test.py::test_local_hook_passes tests/commands/run_test.py::test_local_hook_fails tests/commands/run_test.py::test_meta_hook_passes tests/commands/run_test.py::test_error_with_unstaged_config tests/commands/run_test.py::test_no_unstaged_error_with_all_files_or_files[opts0] tests/commands/run_test.py::test_no_unstaged_error_with_all_files_or_files[opts1] tests/commands/run_test.py::test_files_running_subdir tests/commands/run_test.py::test_pass_filenames[True-hook_args0-foo.py] tests/commands/run_test.py::test_pass_filenames[False-hook_args1-] tests/commands/run_test.py::test_pass_filenames[True-hook_args2-some tests/commands/run_test.py::test_pass_filenames[False-hook_args3-some tests/commands/run_test.py::test_fail_fast tests/commands/run_test.py::test_include_exclude_base_case tests/commands/run_test.py::test_matches_broken_symlink tests/commands/run_test.py::test_include_exclude_total_match tests/commands/run_test.py::test_include_exclude_does_search_instead_of_match tests/commands/run_test.py::test_include_exclude_exclude_removes_files
pre_commit/commands/run.py
pre_commit/commands/run.py