Add --backtracking flag

HISTORY.rst

@@ -1,6 +1,17 @@
 History
 =======
 
+2.6.1 (2022-11-23)
+------------------
+
+* Add ``--backtracking/--no-backtracking`` flag
+  (`backtracking docs <https://pip-compile-multi.readthedocs.io/en/latest/features.html#backtracking-resolver>`_).
+  (Issue `#345`_, PR `#360`_)
+* Bumped ``pip-tools`` minimum version constraint to ``6.8.0`` to support ``--resolver`` option.
+
+.. _#345: https://github.com/peterdemin/pip-compile-multi/issues/345
+.. _#360: https://github.com/peterdemin/pip-compile-multi/pull/360
+
 2.6.0 (2022-11-23)
 ------------------
 
@@ -10,7 +21,7 @@ History
 ------------------
 
 * Add ``--emit_trusted_host/--no-emit_trusted_host`` flag
-  (`docs <https://pip-compile-multi.readthedocs.io/en/latest/features.html#add-trusted-host-annotation>`_).
+  (`trusted host annotation docs <https://pip-compile-multi.readthedocs.io/en/latest/features.html#add-trusted-host-annotation>`_).
   Thanks to `Phil Blackwood`_
   (Issue `#351`_, PR `#353`_).
 

docs/features.rst

@@ -31,6 +31,8 @@ Features
 
 .. automodule:: pipcompilemulti.features.autoresolve
 
+.. automodule:: pipcompilemulti.features.backtracking
+
 .. automodule:: pipcompilemulti.features.skip_constraint_comments
 
 .. automodule:: pipcompilemulti.features.live_output

pipcompilemulti/features/backtracking.py

@@ -0,0 +1,37 @@
+"""
+Backtracking resolver
+=====================
+
+Pip has an option to enable `backtracking`_ conflict resolution logic,
+which can automatically downgrade some dependencies to meet constraints
+from other packages.
+See also the `a note on resolvers`_ in ``pip-compile`` project.
+
+.. code-block:: text
+
+    --backtracking / --no-backtracking
+                                Enable backtracking resolver. Translates to
+                                pip-compile --resolver=backtracking option.
+
+.. _backtracking: https://pip.pypa.io/en/latest/user_guide/\
+        #changes-to-the-pip-dependency-resolver-in-20-3-2020
+.. _a note on resolvers: https://github.com/jazzband/pip-tools#a-note-on-resolvers
+"""
+
+from .base import ClickOption
+from .forward import ForwardOption
+
+
+class Backtracking(ForwardOption):
+    """Enable backtracking resolver."""
+
+    OPTION_NAME = 'backtracking'
+    CLICK_OPTION = ClickOption(
+        long_option='--backtracking/--no-backtracking',
+        is_flag=True,
+        default=False,
+        help_text='Enable backtracking resolver. Translates to '
+                  'pip-compile --resolver=backtracking option.'
+    )
+    enabled_pin_options = ['--resolver=backtracking']
+    disabled_pin_options = ['--resolver=legacy']

pipcompilemulti/features/controller.py

@@ -5,70 +5,73 @@
 
 from .add_hashes import AddHashes
 from .annotate_index import AnnotateIndex
+from .autoresolve import Autoresolve
+from .backtracking import Backtracking
 from .base_dir import BaseDir
+from .build_isolation import BuildIsolation
 from .compatible import Compatible
+from .emit_trusted_host import EmitTrustedHost
+from .extra_index_url import ExtraIndexUrl
 from .file_extensions import InputExtension, OutputExtension
 from .forbid_post import ForbidPost
 from .header import CustomHeader
 from .limit_envs import LimitEnvs
 from .limit_in_paths import LimitInPaths
+from .live_output import LiveOutput
+from .skip_constraint_comments import SkipConstraintComments
 from .unsafe import AllowUnsafe
 from .upgrade import UpgradeAll, UpgradeSelected
 from .use_cache import UseCache
-from .autoresolve import Autoresolve
-from .skip_constraint_comments import SkipConstraintComments
-from .live_output import LiveOutput
-from .extra_index_url import ExtraIndexUrl
-from .build_isolation import BuildIsolation
-from .emit_trusted_host import EmitTrustedHost
 
 
 class FeaturesController:
     """Gateway to a list of features."""
     # pylint: disable=too-many-instance-attributes
 
     def __init__(self):
+        self.add_hashes = AddHashes(self)
+        self.allow_unsafe = AllowUnsafe()
         self.annotate_index = AnnotateIndex()
-        self.use_cache = UseCache()
-        self.input_extension = InputExtension()
-        self.output_extension = OutputExtension()
+        self.autoresolve = Autoresolve()
+        self.backtracking = Backtracking()
         self.base_dir = BaseDir()
+        self.build_isolation = BuildIsolation()
         self.compatible = Compatible()
+        self.emit_trusted_host = EmitTrustedHost()
+        self.extra_index_url = ExtraIndexUrl()
         self.forbid_post = ForbidPost()
-        self.add_hashes = AddHashes(self)
-        self.upgrade_all = UpgradeAll(self)
-        self.upgrade_selected = UpgradeSelected(self)
+        self.header = CustomHeader()
+        self.input_extension = InputExtension()
         self.limit_envs = LimitEnvs(self)
         self.limit_in_paths = LimitInPaths()
-        self.header = CustomHeader()
-        self.allow_unsafe = AllowUnsafe()
-        self.autoresolve = Autoresolve()
-        self.skip_constraint_comments = SkipConstraintComments()
         self.live_output = LiveOutput()
-        self.extra_index_url = ExtraIndexUrl()
-        self.build_isolation = BuildIsolation()
-        self.emit_trusted_host = EmitTrustedHost()
+        self.output_extension = OutputExtension()
+        self.skip_constraint_comments = SkipConstraintComments()
+        self.upgrade_all = UpgradeAll(self)
+        self.upgrade_selected = UpgradeSelected(self)
+        self.use_cache = UseCache()
         self._features = [
+            self.add_hashes,
+            self.allow_unsafe,
             self.annotate_index,
-            self.use_cache,
-            self.input_extension,
-            self.output_extension,
+            self.autoresolve,
+            self.backtracking,
             self.base_dir,
+            self.build_isolation,
             self.compatible,
+            self.emit_trusted_host,
+            self.extra_index_url,
             self.forbid_post,
-            self.add_hashes,
-            self.upgrade_all,
-            self.upgrade_selected,
-            self.limit_in_paths,
-            self.limit_envs,
             self.header,
-            self.allow_unsafe,
-            self.autoresolve,
-            self.skip_constraint_comments,
+            self.input_extension,
+            self.limit_envs,
+            self.limit_in_paths,
             self.live_output,
-            self.extra_index_url,
-            self.build_isolation,
-            self.emit_trusted_host
+            self.output_extension,
+            self.skip_constraint_comments,
+            self.upgrade_all,
+            self.upgrade_selected,
+            self.use_cache,
         ]
 
     def bind(self, command):
@@ -87,15 +90,16 @@ def save_command_options(*args, **kwargs):
     def pin_options(self, in_path):
         """Return list of options to pin command."""
         options = []
-        options.extend(self.use_cache.pin_options())
         options.extend(self.add_hashes.pin_options(in_path))
         options.extend(self.allow_unsafe.pin_options())
-        options.extend(self.upgrade_all.pin_options())
-        options.extend(self.upgrade_selected.pin_options())
         options.extend(self.annotate_index.pin_options())
-        options.extend(self.extra_index_url.pin_options())
+        options.extend(self.backtracking.pin_options())
         options.extend(self.build_isolation.pin_options())
         options.extend(self.emit_trusted_host.pin_options())
+        options.extend(self.extra_index_url.pin_options())
+        options.extend(self.upgrade_all.pin_options())
+        options.extend(self.upgrade_selected.pin_options())
+        options.extend(self.use_cache.pin_options())
         return options
 
     def compose_input_file_path(self, basename):

requirements/base.in

@@ -1,3 +1,3 @@
 click
-pip-tools>=5.2
+pip-tools>=6.8.0
 toposort

requirements/base.txt

@@ -1,4 +1,4 @@
-# SHA1:bf4337d28508b6c39305ca82c70a1c5d34330f8f
+# SHA1:32737333f763ceffd22b7fcb76fbe62a538296fa
 #
 # This file is autogenerated by pip-compile-multi
 # To update, run: