Merge remote-tracking branch 'devxpy/master' into maintenance/merge-3…

…191-3196-3209

- Closes #2200
- Closes #3112 (via merge)

Signed-off-by: Dan Ryan <dan@danryan.co>

pipenv/cli/command.py

@@ -286,7 +286,7 @@ def uninstall(
         three=state.three,
         python=state.python,
         system=state.system,
-        lock=not skip_lock,
+        lock=not state.installstate.skip_lock,
         all_dev=all_dev,
         all=all,
         keep_outdated=state.installstate.keep_outdated,

pipenv/cli/options.py

@@ -127,7 +127,7 @@ def callback(ctx, param, value):
         return value
     return option("--skip-lock", is_flag=True, default=False, expose_value=False,
                   help=u"Skip locking mechanisms and use the Pipfile instead during operation.",
-                  callback=callback, type=click.types.BOOL)(f)
+                  envvar="PIPENV_SKIP_LOCK", callback=callback, type=click.types.BOOL)(f)
 
 
 def keep_outdated_option(f):

pipenv/environments.py

@@ -210,6 +210,17 @@
 if interactive.
 """
 
+PIPENV_SKIP_LOCK = False
+"""If set, Pipenv won't lock dependencies automatically.
+
+This might be desirable if a project has large number of dependencies,
+because locking is an inherently slow operation.
+
+Default is to lock dependencies and update ``Pipfile.lock`` on each run.
+
+NOTE: This only affects the ``install`` and ``uninstall`` commands.
+"""
+
 PIPENV_PYUP_API_KEY = os.environ.get("PIPENV_PYUP_API_KEY", "1ab8d58f-5122e025-83674263-bc1e79e0")
 
 # Internal, support running in a different Python from sys.executable.