-added requires_rez_version, format_version attributes

-warning produced when newer package formats loaded that rez may fail to load

Author: ajohns

src/rez/package_maker__.py

@@ -1,8 +1,10 @@
+from rez.utils._version import _rez_Version
 from rez.utils.schema import Required, schema_keys
 from rez.utils.filesystem import retain_cwd
 from rez.utils.formatting import PackageRequest
 from rez.utils.data_utils import AttrDictWrapper
 from rez.utils.logging_ import print_warning
+from rez.exceptions import PackageMetadataError
 from rez.package_resources_ import help_schema, _commands_schema, \
     _function_schema, late_bound
 from rez.package_repository import create_memory_package_repository
@@ -32,6 +34,8 @@
 
 
 package_schema = Schema({
+    Optional("requires_rez_version"):   And(basestring, Use(Version)),
+
     Required("name"):                   basestring,
     Optional("base"):                   basestring,
     Optional("version"):                Or(basestring,
@@ -92,6 +96,15 @@ def get_package(self):
         package_data = self._get_data()
         package_data = package_schema.validate(package_data)
 
+        # check compatibility with rez version
+        if "requires_rez_version" in package_data:
+            ver = package_data.pop("requires_rez_version")
+
+            if _rez_Version < ver:
+                raise PackageMetadataError(
+                    "Failed reading package definition file: rez version >= %s "
+                    "needed (current version is %s)" % (ver, _rez_Version))
+
         # create a 'memory' package repository containing just this package
         version_str = package_data.get("version") or "_NO_VERSION"
         repo_data = {self.name: {version_str: package_data}}

src/rez/package_resources_.py

@@ -26,7 +26,9 @@
 
 # package attributes that we don't install
 package_build_only_keys = (
+    "requires_rez_version",
     "build_command",
+    "private_build_requires",
     "preprocess",
 )
 

src/rez/utils/_version.py

@@ -1,7 +1,14 @@
 
 
 # Update this value to version up Rez. Do not place anything else in this file.
-_rez_version = "2.11.0"
+_rez_version = "2.12.0"
+
+try:
+    from rez.vendor.version.version import Version
+    _rez_Version = Version(_rez_version)
+except:
+    # the installer imports this file...
+    pass
 
 
 # Copyright 2013-2016 Allan Johns.

src/rezplugins/package_repository/filesystem.py

@@ -11,6 +11,7 @@
     ConfigurationError, PackageRepositoryError
 from rez.utils.formatting import is_valid_package_name, PackageRequest
 from rez.utils.resources import cached_property
+from rez.utils.logging_ import print_warning
 from rez.serialise import load_from_file, FileFormat
 from rez.config import config
 from rez.utils.memcached import memcached, pool_memcached_connections
@@ -22,6 +23,32 @@
 import os
 
 
+#------------------------------------------------------------------------------
+# format version
+#
+# 1:
+# Initial format.
+# 2:
+# Late binding functions added.
+#------------------------------------------------------------------------------
+format_version = 2
+
+
+def check_format_version(filename, data):
+    format_version_ = data.get("format_version")
+
+    if format_version_ is not None:
+        try:
+            format_version_ = int(format_version_)
+        except:
+            return
+
+        if format_version_ > format_version:
+            print_warning(
+                "Loading from %s may fail: newer format version (%d) than current "
+                "format version (%d)" % (filename, format_version_, format_version))
+
+
 #------------------------------------------------------------------------------
 # utilities
 #------------------------------------------------------------------------------
@@ -141,6 +168,7 @@ def _load(self):
                 "Missing package definition file: %r" % self)
 
         data = load_from_file(self.filepath, self.file_format)
+        check_format_version(self.filepath, data)
 
         if "timestamp" not in data:  # old format support
             data_ = self._load_old_formats()
@@ -275,6 +303,7 @@ def iter_packages(self):
     def _load(self):
         format_ = FileFormat[self.ext]
         data = load_from_file(self.filepath, format_)
+        check_format_version(self.filepath, data)
         return data
 
 
@@ -859,6 +888,9 @@ def remove_build_keys(obj):
         overrides = overrides or {}
         overrides["timestamp"] = int(time.time())
 
+        # add the format version
+        package_data["format_version"] = format_version
+
         # apply attribute overrides
         for key, value in overrides.iteritems():
             if package_data.get(key) is None: