# Copyright Spack Project Developers. See COPYRIGHT file for details.
#
# SPDX-License-Identifier: (Apache-2.0 OR MIT)
"""The variant module contains data structures that are needed to manage
variants both in packages and in specs.
"""
import collections.abc
import enum
import functools
import inspect
import itertools
import re
from typing import Any, Callable, Collection, Iterable, List, Optional, Tuple, Type, Union
import llnl.util.lang as lang
import llnl.util.tty.color
import spack.error as error
import spack.spec
import spack.spec_parser
#: These are variant names used by Spack internally; packages can't use them
reserved_names = [
"arch",
"architecture",
"dev_path",
"namespace",
"operating_system",
"os",
"patches",
"platform",
"target",
]
special_variant_values = [None, "none", "*"]
[docs]
class VariantType(enum.Enum):
"""Enum representing the three concrete variant types."""
MULTI = "multi"
BOOL = "bool"
SINGLE = "single"
@property
def variant_class(self) -> Type:
if self is self.MULTI:
return MultiValuedVariant
elif self is self.BOOL:
return BoolValuedVariant
else:
return SingleValuedVariant
[docs]
class Variant:
"""Represents a variant definition, created by the ``variant()`` directive.
There can be multiple definitions of the same variant, and they are given precedence
by order of appearance in the package. Later definitions have higher precedence.
Similarly, definitions in derived classes have higher precedence than those in their
superclasses.
"""
name: str
default: Any
description: str
values: Optional[Collection] #: if None, valid values are defined only by validators
multi: bool
single_value_validator: Callable
group_validator: Optional[Callable]
sticky: bool
precedence: int
def __init__(
self,
name: str,
*,
default: Any,
description: str,
values: Union[Collection, Callable] = (True, False),
multi: bool = False,
validator: Optional[Callable] = None,
sticky: bool = False,
precedence: int = 0,
):
"""Initialize a package variant.
Args:
name: name of the variant
default: default value for the variant, used when nothing is explicitly specified
description: purpose of the variant
values: sequence of allowed values or a callable accepting a single value as argument
and returning True if the value is good, False otherwise
multi: whether multiple values are allowed
validator: optional callable that can be used to perform additional validation
sticky: if true the variant is set to the default value at concretization time
precedence: int indicating precedence of this variant definition in the solve
(definition with highest precedence is used when multiple definitions are possible)
"""
self.name = name
self.default = default
self.description = str(description)
self.values = None
if values == "*":
# wildcard is a special case to make it easy to say any value is ok
self.single_value_validator = lambda v: True
elif isinstance(values, type):
# supplying a type means any value *of that type*
def isa_type(v):
try:
values(v)
return True
except ValueError:
return False
self.single_value_validator = isa_type
elif callable(values):
# If 'values' is a callable, assume it is a single value
# validator and reset the values to be explicit during debug
self.single_value_validator = values
else:
# Otherwise, assume values is the set of allowed explicit values
values = _flatten(values)
self.values = values
self.single_value_validator = lambda v: v in values
self.multi = multi
self.group_validator = validator
self.sticky = sticky
self.precedence = precedence
[docs]
def validate_or_raise(self, vspec: "AbstractVariant", pkg_name: str):
"""Validate a variant spec against this package variant. Raises an
exception if any error is found.
Args:
vspec: variant spec to be validated
pkg_name: the name of the package class that required this validation (for errors)
Raises:
InconsistentValidationError: if ``vspec.name != self.name``
MultipleValuesInExclusiveVariantError: if ``vspec`` has
multiple values but ``self.multi == False``
InvalidVariantValueError: if ``vspec.value`` contains
invalid values
"""
# Check the name of the variant
if self.name != vspec.name:
raise InconsistentValidationError(vspec, self)
# If the value is exclusive there must be at most one
value = vspec.value_as_tuple
if not self.multi and len(value) != 1:
raise MultipleValuesInExclusiveVariantError(vspec, pkg_name)
# Check and record the values that are not allowed
invalid_vals = ", ".join(
f"'{v}'" for v in value if v != "*" and self.single_value_validator(v) is False
)
if invalid_vals:
raise InvalidVariantValueError(
f"invalid values for variant '{self.name}' in package {pkg_name}: {invalid_vals}\n"
)
# Validate the group of values if needed
if self.group_validator is not None and value != ("*",):
self.group_validator(pkg_name, self.name, value)
@property
def allowed_values(self):
"""Returns a string representation of the allowed values for
printing purposes
Returns:
str: representation of the allowed values
"""
# Join an explicit set of allowed values
if self.values is not None:
v = tuple(str(x) for x in self.values)
return ", ".join(v)
# In case we were given a single-value validator
# print the docstring
docstring = inspect.getdoc(self.single_value_validator)
v = docstring if docstring else ""
return v
[docs]
def make_default(self):
"""Factory that creates a variant holding the default value.
Returns:
MultiValuedVariant or SingleValuedVariant or BoolValuedVariant:
instance of the proper variant
"""
return self.make_variant(self.default)
[docs]
def make_variant(self, value) -> "AbstractVariant":
"""Factory that creates a variant holding the value passed as
a parameter.
Args:
value: value that will be hold by the variant
Returns:
MultiValuedVariant or SingleValuedVariant or BoolValuedVariant:
instance of the proper variant
"""
return self.variant_type.variant_class(self.name, value)
@property
def variant_type(self) -> VariantType:
"""String representation of the type of this variant (single/multi/bool)"""
if self.multi:
return VariantType.MULTI
elif self.values == (True, False):
return VariantType.BOOL
else:
return VariantType.SINGLE
def __str__(self):
return (
f"Variant('{self.name}', "
f"default='{self.default}', "
f"description='{self.description}', "
f"values={self.values}, "
f"multi={self.multi}, "
f"single_value_validator={self.single_value_validator}, "
f"group_validator={self.group_validator}, "
f"sticky={self.sticky}, "
f"precedence={self.precedence})"
)
[docs]
def implicit_variant_conversion(method):
"""Converts other to type(self) and calls method(self, other)
Args:
method: any predicate method that takes another variant as an argument
Returns: decorated method
"""
@functools.wraps(method)
def convert(self, other):
# We don't care if types are different as long as I can convert other to type(self)
try:
other = type(self)(other.name, other._original_value, propagate=other.propagate)
except (error.SpecError, ValueError):
return False
return method(self, other)
return convert
def _flatten(values) -> Collection:
"""Flatten instances of _ConditionalVariantValues for internal representation"""
if isinstance(values, DisjointSetsOfValues):
return values
flattened: List = []
for item in values:
if isinstance(item, ConditionalVariantValues):
flattened.extend(item)
else:
flattened.append(item)
# There are parts of the variant checking mechanism that expect to find tuples
# here, so it is important to convert the type once we flattened the values.
return tuple(flattened)
#: Type for value of a variant
ValueType = Union[str, bool, Tuple[Union[str, bool], ...]]
#: Type of variant value when output for JSON, YAML, etc.
SerializedValueType = Union[str, bool, List[Union[str, bool]]]
[docs]
@lang.lazy_lexicographic_ordering
class AbstractVariant:
"""A variant that has not yet decided who it wants to be. It behaves like
a multi valued variant which **could** do things.
This kind of variant is generated during parsing of expressions like
``foo=bar`` and differs from multi valued variants because it will
satisfy any other variant with the same name. This is because it **could**
do it if it grows up to be a multi valued variant with the right set of
values.
"""
name: str
propagate: bool
_value: ValueType
_original_value: Any
def __init__(self, name: str, value: Any, propagate: bool = False):
self.name = name
self.propagate = propagate
# Invokes property setter
self.value = value
[docs]
@staticmethod
def from_node_dict(
name: str, value: Union[str, List[str]], *, propagate: bool = False
) -> "AbstractVariant":
"""Reconstruct a variant from a node dict."""
if isinstance(value, list):
# read multi-value variants in and be faithful to the YAML
mvar = MultiValuedVariant(name, (), propagate=propagate)
mvar._value = tuple(value)
mvar._original_value = mvar._value
return mvar
elif str(value).upper() == "TRUE" or str(value).upper() == "FALSE":
return BoolValuedVariant(name, value, propagate=propagate)
return SingleValuedVariant(name, value, propagate=propagate)
[docs]
def yaml_entry(self) -> Tuple[str, SerializedValueType]:
"""Returns a key, value tuple suitable to be an entry in a yaml dict.
Returns:
tuple: (name, value_representation)
"""
return self.name, list(self.value_as_tuple)
@property
def value_as_tuple(self) -> Tuple[Union[bool, str], ...]:
"""Getter for self.value that always returns a Tuple (even for single valued variants).
This makes it easy to iterate over possible values.
"""
if isinstance(self._value, (bool, str)):
return (self._value,)
return self._value
@property
def value(self) -> ValueType:
"""Returns a tuple of strings containing the values stored in
the variant.
Returns:
tuple: values stored in the variant
"""
return self._value
@value.setter
def value(self, value: ValueType) -> None:
self._value_setter(value)
def _value_setter(self, value: ValueType) -> None:
# Store the original value
self._original_value = value
if not isinstance(value, (tuple, list)):
# Store a tuple of CSV string representations
# Tuple is necessary here instead of list because the
# values need to be hashed
value = tuple(re.split(r"\s*,\s*", str(value)))
for val in special_variant_values:
if val in value and len(value) > 1:
msg = "'%s' cannot be combined with other variant" % val
msg += " values."
raise InvalidVariantValueCombinationError(msg)
# With multi-value variants it is necessary
# to remove duplicates and give an order
# to a set
self._value = tuple(sorted(set(value)))
def _cmp_iter(self) -> Iterable:
yield self.name
yield self.propagate
yield from (str(v) for v in self.value_as_tuple)
[docs]
def copy(self) -> "AbstractVariant":
"""Returns an instance of a variant equivalent to self
Returns:
AbstractVariant: a copy of self
>>> a = MultiValuedVariant('foo', True)
>>> b = a.copy()
>>> assert a == b
>>> assert a is not b
"""
return type(self)(self.name, self._original_value, self.propagate)
[docs]
@implicit_variant_conversion
def satisfies(self, other: "AbstractVariant") -> bool:
"""Returns true if ``other.name == self.name``, because any value that
other holds and is not in self yet **could** be added.
Args:
other: constraint to be met for the method to return True
Returns:
bool: True or False
"""
# If names are different then `self` does not satisfy `other`
# (`foo=bar` will never satisfy `baz=bar`)
return other.name == self.name
[docs]
def intersects(self, other: "AbstractVariant") -> bool:
"""Returns True if there are variant matching both self and other, False otherwise."""
if isinstance(other, (SingleValuedVariant, BoolValuedVariant)):
return other.intersects(self)
return other.name == self.name
[docs]
def compatible(self, other: "AbstractVariant") -> bool:
"""Returns True if self and other are compatible, False otherwise.
As there is no semantic check, two VariantSpec are compatible if
either they contain the same value or they are both multi-valued.
Args:
other: instance against which we test compatibility
Returns:
bool: True or False
"""
# If names are different then `self` is not compatible with `other`
# (`foo=bar` is incompatible with `baz=bar`)
return self.intersects(other)
[docs]
@implicit_variant_conversion
def constrain(self, other: "AbstractVariant") -> bool:
"""Modify self to match all the constraints for other if both
instances are multi-valued. Returns True if self changed,
False otherwise.
Args:
other: instance against which we constrain self
Returns:
bool: True or False
"""
if self.name != other.name:
raise ValueError("variants must have the same name")
old_value = self.value
values = list(sorted(set(self.value_as_tuple + other.value_as_tuple)))
# If we constraint wildcard by another value, just take value
if "*" in values and len(values) > 1:
values.remove("*")
self._value_setter(",".join(str(v) for v in values))
self.propagate = self.propagate and other.propagate
return old_value != self.value
def __contains__(self, item: Union[str, bool]) -> bool:
return item in self.value_as_tuple
def __repr__(self) -> str:
return f"{type(self).__name__}({repr(self.name)}, {repr(self._original_value)})"
def __str__(self) -> str:
delim = "==" if self.propagate else "="
values = spack.spec_parser.quote_if_needed(",".join(str(v) for v in self.value_as_tuple))
return f"{self.name}{delim}{values}"
[docs]
class MultiValuedVariant(AbstractVariant):
"""A variant that can hold multiple values at once."""
[docs]
@implicit_variant_conversion
def satisfies(self, other: AbstractVariant) -> bool:
"""Returns true if ``other.name == self.name`` and ``other.value`` is
a strict subset of self. Does not try to validate.
Args:
other: constraint to be met for the method to return True
Returns:
bool: True or False
"""
super_sat = super().satisfies(other)
if not super_sat:
return False
if "*" in other or "*" in self:
return True
# allow prefix find on patches
if self.name == "patches":
return all(
any(str(w).startswith(str(v)) for w in self.value_as_tuple)
for v in other.value_as_tuple
)
# Otherwise we want all the values in `other` to be also in `self`
return all(v in self for v in other.value_as_tuple)
[docs]
def append(self, value: Union[str, bool]) -> None:
"""Add another value to this multi-valued variant."""
self._value = tuple(sorted((value,) + self.value_as_tuple))
self._original_value = ",".join(str(v) for v in self._value)
def __str__(self) -> str:
# Special-case patches to not print the full 64 character sha256
if self.name == "patches":
values_str = ",".join(str(x)[:7] for x in self.value_as_tuple)
else:
values_str = ",".join(str(x) for x in self.value_as_tuple)
delim = "==" if self.propagate else "="
return f"{self.name}{delim}{spack.spec_parser.quote_if_needed(values_str)}"
[docs]
class SingleValuedVariant(AbstractVariant):
"""A variant that can hold multiple values, but one at a time."""
def _value_setter(self, value: ValueType) -> None:
# Treat the value as a multi-valued variant
super()._value_setter(value)
# Then check if there's only a single value
values = self.value_as_tuple
if len(values) != 1:
raise MultipleValuesInExclusiveVariantError(self)
self._value = values[0]
[docs]
@implicit_variant_conversion
def satisfies(self, other: "AbstractVariant") -> bool:
abstract_sat = super().satisfies(other)
return abstract_sat and (
self.value == other.value or other.value == "*" or self.value == "*"
)
[docs]
def intersects(self, other: "AbstractVariant") -> bool:
return self.satisfies(other)
[docs]
def compatible(self, other: "AbstractVariant") -> bool:
return self.satisfies(other)
[docs]
@implicit_variant_conversion
def constrain(self, other: "AbstractVariant") -> bool:
if self.name != other.name:
raise ValueError("variants must have the same name")
if other.value == "*":
return False
if self.value == "*":
self.value = other.value
return True
if self.value != other.value:
raise UnsatisfiableVariantSpecError(other.value, self.value)
self.propagate = self.propagate and other.propagate
return False
def __contains__(self, item: ValueType) -> bool:
return item == self.value
[docs]
def yaml_entry(self) -> Tuple[str, SerializedValueType]:
assert isinstance(self.value, (bool, str))
return self.name, self.value
def __str__(self) -> str:
delim = "==" if self.propagate else "="
return f"{self.name}{delim}{spack.spec_parser.quote_if_needed(str(self.value))}"
[docs]
class BoolValuedVariant(SingleValuedVariant):
"""A variant that can hold either True or False.
BoolValuedVariant can also hold the value '*', for coerced
comparisons between ``foo=*`` and ``+foo`` or ``~foo``."""
def _value_setter(self, value: ValueType) -> None:
# Check the string representation of the value and turn
# it to a boolean
if str(value).upper() == "TRUE":
self._original_value = value
self._value = True
elif str(value).upper() == "FALSE":
self._original_value = value
self._value = False
elif str(value) == "*":
self._original_value = value
self._value = "*"
else:
msg = 'cannot construct a BoolValuedVariant for "{0}" from '
msg += "a value that does not represent a bool"
raise ValueError(msg.format(self.name))
def __contains__(self, item: ValueType) -> bool:
return item is self.value
def __str__(self) -> str:
sigil = "+" if self.value else "~"
if self.propagate:
sigil *= 2
return f"{sigil}{self.name}"
# The class below inherit from Sequence to disguise as a tuple and comply
# with the semantic expected by the 'values' argument of the variant directive
[docs]
class DisjointSetsOfValues(collections.abc.Sequence):
"""Allows combinations from one of many mutually exclusive sets.
The value ``('none',)`` is reserved to denote the empty set
and therefore no other set can contain the item ``'none'``.
Args:
*sets (list): mutually exclusive sets of values
"""
_empty_set = set(("none",))
def __init__(self, *sets):
self.sets = [set(_flatten(x)) for x in sets]
# 'none' is a special value and can appear only in a set of
# a single element
if any("none" in s and s != set(("none",)) for s in self.sets):
raise error.SpecError(
"The value 'none' represents the empty set,"
" and must appear alone in a set. Use the "
"method 'allow_empty_set' to add it."
)
# Sets should not intersect with each other
if any(s1 & s2 for s1, s2 in itertools.combinations(self.sets, 2)):
raise error.SpecError("sets in input must be disjoint")
#: Attribute used to track values which correspond to
#: features which can be enabled or disabled as understood by the
#: package's build system.
self.feature_values = tuple(itertools.chain.from_iterable(self.sets))
self.default = None
self.multi = True
self.error_fmt = (
"this variant accepts combinations of values from "
"exactly one of the following sets '{values}' "
"@*r{{[{package}, variant '{variant}']}}"
)
[docs]
def with_default(self, default):
"""Sets the default value and returns self."""
self.default = default
return self
[docs]
def with_error(self, error_fmt):
"""Sets the error message format and returns self."""
self.error_fmt = error_fmt
return self
[docs]
def with_non_feature_values(self, *values):
"""Marks a few values as not being tied to a feature."""
self.feature_values = tuple(x for x in self.feature_values if x not in values)
return self
[docs]
def allow_empty_set(self):
"""Adds the empty set to the current list of disjoint sets."""
if self._empty_set in self.sets:
return self
# Create a new object to be returned
object_with_empty_set = type(self)(("none",), *self.sets)
object_with_empty_set.error_fmt = self.error_fmt
object_with_empty_set.feature_values = self.feature_values + ("none",)
return object_with_empty_set
[docs]
def prohibit_empty_set(self):
"""Removes the empty set from the current list of disjoint sets."""
if self._empty_set not in self.sets:
return self
# Create a new object to be returned
sets = [s for s in self.sets if s != self._empty_set]
object_without_empty_set = type(self)(*sets)
object_without_empty_set.error_fmt = self.error_fmt
object_without_empty_set.feature_values = tuple(
x for x in self.feature_values if x != "none"
)
return object_without_empty_set
def __getitem__(self, idx):
return tuple(itertools.chain.from_iterable(self.sets))[idx]
def __len__(self):
return len(itertools.chain.from_iterable(self.sets))
@property
def validator(self):
def _disjoint_set_validator(pkg_name, variant_name, values):
# If for any of the sets, all the values are in it return True
if any(all(x in s for x in values) for s in self.sets):
return
format_args = {"variant": variant_name, "package": pkg_name, "values": values}
msg = self.error_fmt + " @*r{{[{package}, variant '{variant}']}}"
msg = llnl.util.tty.color.colorize(msg.format(**format_args))
raise error.SpecError(msg)
return _disjoint_set_validator
def _a_single_value_or_a_combination(single_value, *values):
error = "the value '" + single_value + "' is mutually exclusive with any of the other values"
return (
DisjointSetsOfValues((single_value,), values)
.with_default(single_value)
.with_error(error)
.with_non_feature_values(single_value)
)
# TODO: The factories below are used by package writers to set values of
# TODO: multi-valued variants. It could be worthwhile to gather them in
# TODO: a common namespace (like 'multi') in the future.
[docs]
def any_combination_of(*values):
"""Multi-valued variant that allows any combination of the specified
values, and also allows the user to specify 'none' (as a string) to choose
none of them.
It is up to the package implementation to handle the value 'none'
specially, if at all.
Args:
*values: allowed variant values
Returns:
a properly initialized instance of DisjointSetsOfValues
"""
return _a_single_value_or_a_combination("none", *values)
[docs]
def auto_or_any_combination_of(*values):
"""Multi-valued variant that allows any combination of a set of values
(but not the empty set) or 'auto'.
Args:
*values: allowed variant values
Returns:
a properly initialized instance of DisjointSetsOfValues
"""
return _a_single_value_or_a_combination("auto", *values)
#: Multi-valued variant that allows any combination picking
#: from one of multiple disjoint sets
[docs]
def disjoint_sets(*sets):
"""Multi-valued variant that allows any combination picking from one
of multiple disjoint sets of values, and also allows the user to specify
'none' (as a string) to choose none of them.
It is up to the package implementation to handle the value 'none'
specially, if at all.
Args:
*sets:
Returns:
a properly initialized instance of DisjointSetsOfValues
"""
return DisjointSetsOfValues(*sets).allow_empty_set().with_default("none")
[docs]
@functools.total_ordering
class ConditionalValue:
"""Conditional value for a variant."""
value: Any
# optional because statically disabled values (when=False) are set to None
# when=True results in spack.spec.Spec()
when: Optional["spack.spec.Spec"]
def __init__(self, value: Any, when: Optional["spack.spec.Spec"]):
self.value = value
self.when = when
def __repr__(self):
return f"ConditionalValue({self.value}, when={self.when})"
def __str__(self):
return str(self.value)
def __hash__(self):
# Needed to allow testing the presence of a variant in a set by its value
return hash(self.value)
def __eq__(self, other):
if isinstance(other, (str, bool)):
return self.value == other
return self.value == other.value
def __lt__(self, other):
if isinstance(other, str):
return self.value < other
return self.value < other.value
[docs]
def prevalidate_variant_value(
pkg_cls: "Type[spack.package_base.PackageBase]",
variant: AbstractVariant,
spec: Optional["spack.spec.Spec"] = None,
strict: bool = False,
) -> List[Variant]:
"""Do as much validation of a variant value as is possible before concretization.
This checks that the variant value is valid for *some* definition of the variant, and
it raises if we know *before* concretization that the value cannot occur. On success
it returns the variant definitions for which the variant is valid.
Arguments:
pkg_cls: package in which variant is (potentially multiply) defined
variant: variant spec with value to validate
spec: optionally restrict validation only to variants defined for this spec
strict: if True, raise an exception if no variant definition is valid for any
constraint on the spec.
Return:
list of variant definitions that will accept the given value. List will be empty
only if the variant is a reserved variant.
"""
# don't validate wildcards or variants with reserved names
if variant.value == ("*",) or variant.name in reserved_names or variant.propagate:
return []
# raise if there is no definition at all
if not pkg_cls.has_variant(variant.name):
raise UnknownVariantError(
f"No such variant '{variant.name}' in package {pkg_cls.name}", [variant.name]
)
# do as much prevalidation as we can -- check only those
# variants whose when constraint intersects this spec
errors = []
possible_definitions = []
valid_definitions = []
for when, pkg_variant_def in pkg_cls.variant_definitions(variant.name):
if spec and not spec.intersects(when):
continue
possible_definitions.append(pkg_variant_def)
try:
pkg_variant_def.validate_or_raise(variant, pkg_cls.name)
valid_definitions.append(pkg_variant_def)
except spack.error.SpecError as e:
errors.append(e)
# value is valid for at least one definition -- return them all
if valid_definitions:
return valid_definitions
# no when spec intersected, so no possible definition for the variant in this configuration
if strict and not possible_definitions:
when_clause = f" when {spec}" if spec else ""
raise InvalidVariantValueError(
f"variant '{variant.name}' does not exist for '{pkg_cls.name}'{when_clause}"
)
# There are only no errors if we're not strict and there are no possible_definitions.
# We are strict for audits but not for specs on the CLI or elsewhere. Being strict
# in these cases would violate our rule of being able to *talk* about any configuration,
# regardless of what the package.py currently says.
if not errors:
return []
# if there is just one error, raise the specific error
if len(errors) == 1:
raise errors[0]
# otherwise combine all the errors and raise them together
raise InvalidVariantValueError(
"multiple variant issues:", "\n".join(e.message for e in errors)
)
[docs]
class ConditionalVariantValues(lang.TypedMutableSequence):
"""A list, just with a different type"""
[docs]
class DuplicateVariantError(error.SpecError):
"""Raised when the same variant occurs in a spec twice."""
[docs]
class UnknownVariantError(error.SpecError):
"""Raised when an unknown variant occurs in a spec."""
def __init__(self, msg: str, unknown_variants: List[str]):
super().__init__(msg)
self.unknown_variants = unknown_variants
[docs]
class InconsistentValidationError(error.SpecError):
"""Raised if the wrong validator is used to validate a variant."""
def __init__(self, vspec, variant):
msg = 'trying to validate variant "{0.name}" ' 'with the validator of "{1.name}"'
super().__init__(msg.format(vspec, variant))
[docs]
class MultipleValuesInExclusiveVariantError(error.SpecError, ValueError):
"""Raised when multiple values are present in a variant that wants
only one.
"""
def __init__(self, variant: AbstractVariant, pkg_name: Optional[str] = None):
pkg_info = "" if pkg_name is None else f" in package '{pkg_name}'"
msg = f"multiple values are not allowed for variant '{variant.name}'{pkg_info}"
super().__init__(msg.format(variant, pkg_info))
[docs]
class InvalidVariantValueCombinationError(error.SpecError):
"""Raised when a variant has values '*' or 'none' with other values."""
[docs]
class InvalidVariantValueError(error.SpecError):
"""Raised when variants have invalid values."""
[docs]
class UnsatisfiableVariantSpecError(error.UnsatisfiableSpecError):
"""Raised when a spec variant conflicts with package constraints."""
def __init__(self, provided, required):
super().__init__(provided, required, "variant")