Recover from invalid python virtualenvs

pre_commit/languages/all.py

@@ -21,6 +21,9 @@ from pre_commit.languages import system
 #     return 'default' if there is no better option.
 #    """
 #
+# def healthy(repo_cmd_runner, language_version):
+#     """Return whether or not the environment is considered functional."""
+#
 # def install_environment(repo_cmd_runner, version, additional_dependencies):
 #     """Installs a repository in the given repository.  Note that the current
 #     working directory will already be inside the repository.

pre_commit/languages/docker.py

@@ -15,6 +15,7 @@ from pre_commit.xargs import xargs
 ENVIRONMENT_DIR = 'docker'
 PRE_COMMIT_LABEL = 'PRE_COMMIT'
 get_default_version = helpers.basic_get_default_version
+healthy = helpers.basic_healthy
 
 
 def md5(s):  # pragma: windows no cover

pre_commit/languages/golang.py

@@ -15,6 +15,7 @@ from pre_commit.xargs import xargs
 
 ENVIRONMENT_DIR = 'golangenv'
 get_default_version = helpers.basic_get_default_version
+healthy = helpers.basic_healthy
 
 
 def get_env_patch(venv):

pre_commit/languages/helpers.py

@@ -37,3 +37,7 @@ def assert_no_additional_deps(lang, additional_deps):
 
 def basic_get_default_version():
     return 'default'
+
+
+def basic_healthy(repo_cmd_runner, language_version):
+    return True

pre_commit/languages/node.py

@@ -13,6 +13,7 @@ from pre_commit.xargs import xargs
 
 ENVIRONMENT_DIR = 'node_env'
 get_default_version = helpers.basic_get_default_version
+healthy = helpers.basic_healthy
 
 
 def get_env_patch(venv):  # pragma: windows no cover

pre_commit/languages/pcre.py

@@ -9,6 +9,7 @@ from pre_commit.xargs import xargs
 ENVIRONMENT_DIR = None
 GREP = 'ggrep' if sys.platform == 'darwin' else 'grep'
 get_default_version = helpers.basic_get_default_version
+healthy = helpers.basic_healthy
 
 
 def install_environment(repo_cmd_runner, version, additional_dependencies):

pre_commit/languages/python.py

@@ -10,11 +10,11 @@ from pre_commit.envcontext import Var
 from pre_commit.languages import helpers
 from pre_commit.parse_shebang import find_executable
 from pre_commit.util import clean_path_on_failure
+from pre_commit.util import cmd_output
 from pre_commit.xargs import xargs
 
 
 ENVIRONMENT_DIR = 'py_env'
-get_default_version = helpers.basic_get_default_version
 
 
 def bin_dir(venv):
@@ -83,6 +83,14 @@ def get_default_version():
         return get_default_version()
 
 
+def healthy(repo_cmd_runner, language_version):
+    with in_env(repo_cmd_runner, language_version):
+        retcode, _, _ = cmd_output(
+            'python', '-c', 'import datetime, io, os, weakref', retcode=None,
+        )
+    return retcode == 0
+
+
 def norm_version(version):
     if os.name == 'nt':  # pragma: no cover (windows)
         # Try looking up by name

pre_commit/languages/ruby.py

@@ -17,6 +17,7 @@ from pre_commit.xargs import xargs
 
 ENVIRONMENT_DIR = 'rbenv'
 get_default_version = helpers.basic_get_default_version
+healthy = helpers.basic_healthy
 
 
 def get_env_patch(venv, language_version):  # pragma: windows no cover

pre_commit/languages/script.py

@@ -6,6 +6,7 @@ from pre_commit.xargs import xargs
 
 ENVIRONMENT_DIR = None
 get_default_version = helpers.basic_get_default_version
+healthy = helpers.basic_healthy
 
 
 def install_environment(repo_cmd_runner, version, additional_dependencies):

pre_commit/languages/swift.py

@@ -11,6 +11,7 @@ from pre_commit.xargs import xargs
 
 ENVIRONMENT_DIR = 'swift_env'
 get_default_version = helpers.basic_get_default_version
+healthy = helpers.basic_healthy
 BUILD_DIR = '.build'
 BUILD_CONFIG = 'release'
 

pre_commit/languages/system.py

@@ -6,6 +6,7 @@ from pre_commit.xargs import xargs
 
 ENVIRONMENT_DIR = None
 get_default_version = helpers.basic_get_default_version
+healthy = helpers.basic_healthy
 
 
 def install_environment(repo_cmd_runner, version, additional_dependencies):