Add use option to sources, and default-use to the settings.

`default-use` is true by default.  When false, the source is not
checked out, and the version for this package is not overridden.

Part of plone/Products.CMFPlone#3670

CHANGES.rst

@@ -4,7 +4,10 @@ Changes
 3.0.0b2 (unreleased)
 --------------------
 
-- Nothing changed yet.
+- Add ``use`` option to sources, and ``default-use`` to the settings.
+  ``default-use`` is true by default.  When false, the source is not
+  checked out, and the version for this package is not overridden.
+  [maurits]
 
 
 3.0.0b1 (2022-11-21)

README.rst

@@ -107,6 +107,10 @@ In the main sections the input and output files are defined.
             somefancypackage
             otherpackage
 
+``default-use``:
+  True by default.  When false, the source is not checked out,
+  and the version for this package is not overridden.
+
 Additional, custom variables can be defined as ``key = value`` pair.
 Those can be referenced in other values as ``${settings:key}`` and will be expanded there.
 
@@ -158,6 +162,11 @@ All other sections are defining the sources to be used.
 
     Defaults to default mode configured in main section ``[settings]`` ``default-install-mode =`` value.
 
+``use``:
+  True by default, unless ``default-use`` in the general settings is false.
+  When false, the source is not checked out,
+  and the version for this package is not overridden.
+
 ``submodules``
     There are 3 different options
 

setup.cfg

@@ -85,3 +85,9 @@ universal = 1
 # TODO: Remove current max-line-lengh ignore in follow-up and adopt black limit.
 # max-line-length = 88
 ignore = D001
+
+
+[check-manifest]
+ignore =
+    Makefile
+    mx.ini

src/mxdev/config.py

@@ -10,6 +10,14 @@
     from .hooks import Hook
 
 
+def to_bool(value):
+    if not isinstance(value, str):
+        return bool(value)
+    if value.lower() in ("true", "on", "yes", "1"):
+        return True
+    return False
+
+
 class Configuration:
     settings: typing.Dict[str, str]
     overrides: typing.Dict[str, str]
@@ -48,6 +56,7 @@ def __init__(
         if mode not in ["direct", "skip"]:
             raise ValueError("default-install-mode must be one of 'direct' or 'skip'")
 
+        default_use = to_bool(settings.get("default-use", True))
         raw_overrides = settings.get("version-overrides", "").strip()
         self.overrides = {}
         for line in raw_overrides.split("\n"):
@@ -80,7 +89,10 @@ def is_ns_member(name):
                 self.hooks[name] = self._read_section(data, name)
                 continue
             logger.debug(f"Section '{name}' belongs to package")
-            package = self.packages[name] = self._read_section(data, name)
+            package = self._read_section(data, name)
+            if not to_bool(package.get("use", default_use)):
+                continue
+            self.packages[name] = package
             if settings.get("offline", False):
                 package.setdefault("offline", True)
             # XXX: name should not be necessary in WorkingCopies