Deprecate omittable_distros in favor of stub_distros

Stub_distros is more powerful and flexible. This will automatically convert
any existing omittable_distros in configs to config stub_distros. It shows
a warning about converting any omittable_distros encountered to stubs.

Author: MHendricks

README.md

@@ -1404,26 +1404,10 @@ create a stub for the requirement `the_dcc==1.3` but not for a requirement of
 
 ### Omittable Distros
 
-The `omittable_distros` key in [config](#config) definitions are used to specify distros
-that are not required to use this hab configuration. This can be used to make it
-so not all hosts need to have a dcc installed. For example a producer likely will
-never need to open houdini but does need access to external tools. You would need
-to install Houdini(or create a empty .hab.json distro) so hab doesn't raise an
-`InvalidRequirementError` when it can't find Houdini.
-
-```json5
-    "distros": [
-        "houdini20.0==20.0.688",
-        "SideFXLabs20.0==20.0.506",
-        "python_tools"
-    ],
-    "omittable_distros": [
-        "houdini20.0",
-        "SideFXLabs20.0"
-    ]
-```
-This will make it so `houdini20.0` and `SideFXLabs20.0` will be loaded if found,
-but if not they will be ignored. `python_tools` will always need to be installed.
+The `omittable_distros` key in [config](#config) definitions is deprecated and should
+be converted to config based [stub_distros](#stub-distros). For now hab will automatically
+do this conversion but will print a warning when it does. This will be removed
+in the future. The Config `omittable_distros` property has been removed.
 
 Note: `omittable_distros` is a list of distro names. It does not accept specifier
 arguments like `==20.0.688`.

hab/parsers/config.py

@@ -129,20 +129,26 @@ def load(self, filename):
         data = super().load(filename)
         self._alias_mods = data.get("alias_mods", NotSet)
         self.inherits = data.get("inherits", NotSet)
-        if self.omittable_distros is NotSet:
-            self.omittable_distros = data.get("omittable_distros", NotSet)
         if self.stub_distros is NotSet:
             self.stub_distros = data.get("stub_distros", NotSet)
-        return data
 
-    @hab_property(verbosity=3, process_order=50)
-    def omittable_distros(self):
-        """A collection of distro names that are ignored if required by distros."""
-        return self.frozen_data.get("omittable_distros", NotSet)
+        # Handle legacy omittable_distros by convert it to stub_distros.
+        # NOTE: This will be removed in a future version of hab.
+        omittable_distros = data.get("omittable_distros", [])
+        for distro in omittable_distros:
+            # Only log these warnings if this config is flattened. This prevents
+            # showing the warning every time hab resolves its configuration
+            self.log_on_resolve(
+                logging.WARNING,
+                'omittable_distros is deprecated, move "{}" to stub_distros '
+                'in "{}".'.format(distro, self.filename),
+                logger=logger,
+            )
+            if self.stub_distros is NotSet:
+                self.stub_distros = {}
+            self.stub_distros.setdefault("set", {}).setdefault(distro, {})
 
-    @omittable_distros.setter
-    def omittable_distros(self, value):
-        self.frozen_data["omittable_distros"] = value
+        return data
 
     @hab_property(verbosity=3)
     def stub_distros(self):

hab/parsers/flat_config.py

@@ -231,9 +231,7 @@ def versions(self):
 
             # Apply the config level stub_distros before resolving
             with self.resolver.site.stub_distros_override(self.stub_distros):
-                reqs = self.resolver.resolve_requirements(
-                    distros, omittable=self.omittable_distros
-                )
+                reqs = self.resolver.resolve_requirements(distros)
             for req in reqs.values():
                 version = self.resolver.find_distro(req)
                 versions.append(version)

hab/resolver.py

@@ -594,14 +594,11 @@ def resolve(self, uri, forced_requirements=None):
             if forced_requirements is not None:
                 self.forced_requirements = current
 
-    def resolve_requirements(self, requirements, omittable=None):
+    def resolve_requirements(self, requirements):
         """Recursively solve the provided requirements into a final list of requirements.
 
         Args:
             requirements (list): The requirements to resolve.
-            omittable (list, optional): A list of distro names that are not required.
-                If a suitable distro can not be found, normally an `InvalidRequirementError`
-                is raised. If that distro name is in this list a warning is logged instead.
 
         Raises:
             MaxRedirectError: Redirect limit reached, unable to resolve the requested
@@ -611,9 +608,7 @@ def resolve_requirements(self, requirements, omittable=None):
         if isinstance(requirements, list):
             requirements = Solver.simplify_requirements(requirements)
 
-        solver = Solver(
-            requirements, self, forced=self.forced_requirements, omittable=omittable
-        )
+        solver = Solver(requirements, self, forced=self.forced_requirements)
         return solver.resolve()
 
     def uri_validate(self, uri):

hab/solvers.py

@@ -18,18 +18,14 @@ class Solver(object):
         forced (dict, optional): Forces this distro requirement replacing any resolved
             requirements. Using this may lead to configuring your environment
             incorrectly, use with caution.
-        omittable (list, optional): A list of distro names that are not required.
-            If a suitable distro can not be found, normally an `InvalidRequirementError`
-            is raised. If that distro name is in this list a warning is logged instead.
 
     Attributes:
         invalid (dict, optional): If a recursive requirement makes a already resolved
             version invalid, that version is added to this list as an exclusive exclude.
     """
 
-    def __init__(self, requirements, resolver, forced=None, omittable=None):
+    def __init__(self, requirements, resolver, forced=None):
         self.forced = forced if forced else {}
-        self.omittable = omittable if omittable else []
         self.invalid = {}
         self.max_redirects = 2
         self.requirements = requirements
@@ -130,10 +126,6 @@ def _resolve(
                 logger.warning(f"Forced Requirement: {req}")
                 reported.add(name)
 
-            if name in self.omittable and name not in self.resolver.distros:
-                logger.warning(f"Skipping missing omitted requirement: {req}")
-                continue
-
             # Update the requirement to match all current requirements
             req = self.append_requirement(resolved, req)
             if name in self.invalid:

tests/configs/stub/stub_omittable.json

@@ -0,0 +1,13 @@
+{
+    "name": "omittable",
+    "description": "Legacy testing for omittable_distros. This is replaced by stub_distros.",
+    "context": ["stub"],
+    "inherits": false,
+    "distros": {
+        "maya2024": null
+    },
+    "omittable_distros": [
+        "missing_dcc",
+        "non-existent-distro"
+    ]
+}

tests/resolver_freeze_configs.json

@@ -367,6 +367,22 @@
         ]
     },
     "stub": "Error resolving stub: Unable to find a distro for requirement: invalid",
+    "stub/omittable": {
+        "context": [
+            "stub"
+        ],
+        "name": "omittable",
+        "stub_distros": {
+            "set": {
+                "missing_dcc": {},
+                "non-existent-distro": {}
+            }
+        },
+        "uri": "stub/omittable",
+        "versions": [
+            "maya2024==2024.0"
+        ]
+    },
     "stub/override": "Error resolving stub/override: Unable to find a distro for requirement: invalid",
     "verbosity": {
         "context": [],

tests/site_main_check.habcache

@@ -522,6 +522,21 @@
                 "inherits": false,
                 "name": "stub"
             },
+            "{config-root}/configs/stub/stub_omittable.json": {
+                "context": [
+                    "stub"
+                ],
+                "description": "Legacy testing for omittable_distros. This is replaced by stub_distros.",
+                "distros": {
+                    "maya2024": null
+                },
+                "inherits": false,
+                "name": "omittable",
+                "omittable_distros": [
+                    "missing_dcc",
+                    "non-existent-distro"
+                ]
+            },
             "{config-root}/configs/stub/stub_override.json": {
                 "context": [
                     "stub"