[+] unified resolver: constraints_t, resolver_base_t, requested flag

1. add resolver/common.py with constraints_t class holding all constraints
     with filtered property views (install, excluded, ignored, pinned,
     upgrade, requested) and resolver_base_t abstract base class;
  2. refactor resolver/general.py: extend resolver_base_t, resolve() takes
     constraints_t, add resolve_specs() classmethod convenience for tests;
  3. refactor resolver/solv.py: solv_resolver_t extends resolver_base_t,
     fix pkg_spec NameError in error messages, remove duplicate parse_reference;
  4. add requested flag to package_constraint_t for tracking user-specified
     packages vs reference pins;
  5. update test_resolver.py and test_solv_backend.py for new interface;

python/online/fxreader/pr34/commands_typed/archlinux/resolver/common.py

@@ -0,0 +1,91 @@
+"""Common resolver interface and constraint preprocessing."""
+
+import abc
+
+from ..apps.specs.models import (
+	constraint_op_t,
+	package_constraint_t,
+	package_index_t,
+	resolve_result_t,
+)
+
+
+class constraints_t:
+	"""Holds all constraints from all sources. Provides filtered views."""
+
+	def __init__(self) -> None:
+		self._all: list[package_constraint_t] = []
+
+	def add(self, c: package_constraint_t) -> None:
+		self._all.append(c)
+
+	def add_spec(self, spec: str, requested: bool = False) -> None:
+		c = package_constraint_t.parse(spec)
+		if requested:
+			c.requested = True
+		self._all.append(c)
+
+	def add_pinned(self, name: str, version: str) -> None:
+		self._all.append(package_constraint_t(
+			name=name, op=constraint_op_t.eq, version=version, pinned=True,
+		))
+
+	def add_upgrade(self, name: str) -> None:
+		self._all.append(package_constraint_t(name=name, upgrade=True))
+
+	@property
+	def ignored_names(self) -> set[str]:
+		return {c.name for c in self._all if c.ignore}
+
+	@property
+	def excluded_names(self) -> set[str]:
+		return {c.name for c in self._all if c.exclude}
+
+	@property
+	def skip_names(self) -> set[str]:
+		return self.ignored_names | self.excluded_names
+
+	@property
+	def install(self) -> list[package_constraint_t]:
+		skip = self.skip_names
+		return [c for c in self._all if not c.ignore and not c.exclude and c.name not in skip]
+
+	@property
+	def pinned(self) -> dict[str, str]:
+		skip = self.skip_names
+		result: dict[str, str] = {}
+		for c in self._all:
+			if c.pinned and c.op is constraint_op_t.eq and c.version is not None and c.name not in skip:
+				result[c.name] = c.version
+		return result
+
+	@property
+	def requested_names(self) -> set[str]:
+		return {c.name for c in self._all if c.requested}
+
+	@property
+	def upgrade_names(self) -> set[str]:
+		return {c.name for c in self._all if c.upgrade}
+
+	def filter_pinned(self, pinned: dict[str, str]) -> dict[str, str]:
+		skip = self.skip_names
+		return {k: v for k, v in pinned.items() if k not in skip}
+
+	@classmethod
+	def from_specs(cls, specs: list[str], requested: bool = False) -> 'constraints_t':
+		result = cls()
+		for spec in specs:
+			result.add_spec(spec, requested=requested)
+		return result
+
+
+class resolver_base_t(abc.ABC):
+	"""Common interface for all resolver backends."""
+
+	@abc.abstractmethod
+	def resolve(
+		self,
+		constraints: constraints_t,
+		indices: list[package_index_t],
+	) -> resolve_result_t:
+		raise NotImplementedError

python/online/fxreader/pr34/commands_typed/archlinux/resolver/general.py

@@ -1,21 +1,20 @@
-import dataclasses
 import logging
 
-from typing import (
-	Optional,
-)
+from typing import Optional
 
-from ..models import (
+from ..apps.specs.models import (
 	package_t,
 	package_constraint_t,
 	package_index_t,
 	resolve_result_t,
 )
 
+from .common import constraints_t, resolver_base_t
+
 logger = logging.getLogger(__name__)
 
 
-class resolver_t:
+class resolver_t(resolver_base_t):
 	class error_t:
 		class not_found_t(Exception):
 			def __init__(self, name: str) -> None:
@@ -63,26 +62,36 @@ class resolver_t:
 
 		return None
 
-	@staticmethod
-	def resolve(
-		packages: list[str],
+	@classmethod
+	def resolve_specs(
+		cls,
+		specs: list[str],
 		indices: list[package_index_t],
-		skip_installed: Optional[set[str]] = None,
 	) -> resolve_result_t:
-		if skip_installed is None:
-			skip_installed = set()
+		"""Convenience: parse raw specs and resolve."""
+		return cls().resolve(constraints_t.from_specs(specs), indices)
 
+	def resolve(
+		self,
+		constraints: constraints_t,
+		indices: list[package_index_t],
+	) -> resolve_result_t:
+		excluded = constraints.excluded_names
+
+		ignored = constraints.ignored_names
 		result = resolve_result_t()
 		visited: set[str] = set()
 		stack: list[tuple[package_constraint_t, Optional[str]]] = []
 
-		for pkg_str in packages:
-			constraint = package_constraint_t.parse(pkg_str)
+		for constraint in constraints.install:
 			stack.append((constraint, None))
 
 		while len(stack) > 0:
 			constraint, parent = stack.pop()
 
+			if constraint.name in excluded:
+				continue
+
 			if constraint.name in visited:
 				if constraint.name in result.resolved:
 					pkg = result.resolved[constraint.name]
@@ -93,7 +102,7 @@ class resolver_t:
 						)
 				continue
 
-			if constraint.name in skip_installed:
+			if constraint.name in ignored:
 				visited.add(constraint.name)
 				continue
 
@@ -152,7 +161,7 @@ class resolver_t:
 						)
 
 			for dep in pkg.depends:
-				if dep.name not in visited and dep.name not in skip_installed:
+				if dep.name not in visited and dep.name not in ignored:
 					stack.append((dep, pkg.name))
 
 		return result

python/online/fxreader/pr34/commands_typed/archlinux/resolver/solv.py

@@ -15,13 +15,17 @@ from typing import (
 	Any,
 )
 
-from ..models import (
+from ..apps.specs.models import (
+	constraint_op_t,
 	package_t,
 	package_index_t,
 	package_constraint_t,
 	resolve_result_t,
+	vercmp_t,
 )
 
+from .common import constraints_t, resolver_base_t
+
 from .solv_types import (
 	solv_package_t,
 	solv_index_t,
@@ -195,20 +199,6 @@ class solv_pool_t:
 				expanded.append(pkg_name)
 		return expanded
 
-	@staticmethod
-	def parse_reference(txt: str) -> dict[str, str]:
-		pinned: dict[str, str] = {}
-		for line in txt.splitlines():
-			line = line.strip()
-			if line == '' or line.startswith('#'):
-				continue
-			parts = line.split()
-			pkg_spec = parts[0]
-			if '==' in pkg_spec:
-				name, version = pkg_spec.split('==', 1)
-				pinned[name] = version
-		return pinned
-
 	def resolve(
 		self,
 		packages: list[str],
@@ -232,15 +222,11 @@ class solv_pool_t:
 				upgrade_packages = self.expand_groups(upgrade_packages)
 			upgrade_set = set(upgrade_packages)
 
-		for pkg_spec in packages:
-			pkg_name = (
-				pkg_spec.split('>=')[0]
-				.split('<=')[0]
-				.split('>')[0]
-				.split('<')[0]
-				.split('==')[0]
-				.split('=')[0]
-			)
+		rc = constraints_t.from_specs(packages)
+		excluded = rc.excluded_names
+
+		for constraint in rc.install:
+			pkg_name = constraint.name
 
 			target_evr: Optional[str] = None
 			if (
@@ -249,36 +235,62 @@ class solv_pool_t:
 				and pkg_name not in upgrade_set
 			):
 				target_evr = pinned[pkg_name]
-			elif pkg_name != pkg_spec and '==' in pkg_spec:
-				target_evr = pkg_spec.split('==', 1)[1]
+			elif constraint.op is not None and constraint.op is constraint_op_t.eq:
+				target_evr = constraint.version
 
 			sel = self._pool.select(
 				pkg_name,
 				solv.Selection.SELECTION_NAME,
 			)
 			if sel.isempty():
-				result.problems.append('package not found: %s' % pkg_spec)
+				result.problems.append('package not found: %s' % pkg_name)
 				continue
 
 			if target_evr is not None:
-				# match by exact name + version, never via provides hijack
+				# exact version match
 				matching = [s for s in sel.solvables() if s.evr == target_evr]
 				if len(matching) == 0:
 					result.problems.append(
 						'no name match for %s==%s' % (pkg_name, target_evr)
 					)
 					continue
-				# pick exactly one solvable — multiple snapshots may yield
-				# duplicates of the same pkg which libsolv considers conflicting
 				jobs.append(
 					self._pool.Job(
 						solv.Job.SOLVER_INSTALL | solv.Job.SOLVER_SOLVABLE,
 						matching[0].id,
 					)
 				)
+			elif constraint.op is not None and constraint.version is not None:
+				# version constraint (<, <=, >=, >) — filter solvables
+				matching = [
+					s for s in sel.solvables()
+					if constraint.satisfied_by(str(s.evr))
+				]
+				if len(matching) == 0:
+					result.problems.append(
+						'no version satisfies %s' % constraint.to_str()
+					)
+					continue
+				# pick the best: for < and <= pick highest matching, for > and >= also highest
+				best = matching[0]
+				for s in matching[1:]:
+					if vercmp_t.vercmp(str(s.evr), str(best.evr)) > 0:
+						best = s
+				jobs.append(
+					self._pool.Job(
+						solv.Job.SOLVER_INSTALL | solv.Job.SOLVER_SOLVABLE,
+						best.id,
+					)
+				)
 			else:
 				jobs += sel.jobs(solv.Job.SOLVER_INSTALL)
 
+		# add exclusion jobs — lock excluded packages as not installable
+		for excl_name in excluded:
+			excl_sel = self._pool.select(excl_name, solv.Selection.SELECTION_NAME)
+			if not excl_sel.isempty():
+				jobs += excl_sel.jobs(solv.Job.SOLVER_LOCK)
+
 		if len(result.problems) > 0:
 			return result
 
@@ -292,6 +304,10 @@ class solv_pool_t:
 		trans = solver.transaction()
 		new_solvables = list(trans.newsolvables())
 		for s in new_solvables:
+			if s.name in excluded:
+				raise RuntimeError(
+					'libsolv resolved excluded package %s — exclusion constraint violated' % s.name
+				)
 			result.resolved[s.name] = s
 
 		if logger.isEnabledFor(logging.DEBUG):
@@ -365,16 +381,14 @@ class solv_pool_t:
 			)
 
 
-def resolve(
-	indices: list[package_index_t],
-	packages: list[str],
-	pinned: Optional[dict[str, str]] = None,
-	upgrade_packages: Optional[list[str]] = None,
-) -> resolve_result_t:
-	"""Resolve using libsolv. Takes general types, returns general types.
+class solv_resolver_t(resolver_base_t):
+	"""Libsolv-based resolver implementing the common interface."""
 
-	Converts package_index_t → solv_index_t internally.
-	"""
+	def resolve(
+		self,
+		constraints: 'constraints_t',
+		indices: list[package_index_t],
+	) -> resolve_result_t:
 		# convert general → solv internal types
 		stores: list[repo_store_t] = []
 		for idx in indices:
@@ -397,6 +411,15 @@ def resolve(
 
 		pool = solv_pool_t(stores=stores)
 
+		# build raw package specs for solv_pool_t.resolve
+		packages: list[str] = [c.to_str() for c in constraints.install]
+		for name in constraints.excluded_names:
+			packages.append('!%s' % name)
+
+		pinned = constraints.pinned or None
+		upgrade_names = constraints.upgrade_names
+		upgrade_packages = list(upgrade_names) if len(upgrade_names) > 0 else None
+
 		solv_result = pool.resolve(
 			packages=packages,
 			pinned=pinned,
@@ -408,7 +431,6 @@ def resolve(
 		result.problems = list(solv_result.problems)
 
 		for pkg_name, solvable in solv_result.resolved.items():
-		# find the general package_t matching this solvable by name+version
 			for idx in indices:
 				version_map = idx.packages.get(pkg_name)
 				if version_map is None:

python/online/fxreader/pr34/commands_typed/archlinux/resolver/types.py

@@ -1,6 +1,6 @@
 """Re-export general types from models for convenience."""
 
-from ..models import (
+from ..apps.specs.models import (
 	package_t,
 	package_index_t,
 	resolve_result_t,

python/online/fxreader/pr34/commands_typed/archlinux/tests/test_resolver.py

@@ -2,7 +2,7 @@ import unittest
 from typing import Optional
 
 from ..resolver.general import resolver_t
-from ..models import (
+from ..apps.specs.models import (
 	package_t,
 	package_index_t,
 	package_constraint_t,
@@ -45,7 +45,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['bash'], [idx])
+		result = resolver_t.resolve_specs(['bash'], [idx])
 
 		self.assertIn('bash', result.resolved)
 		self.assertEqual(result.resolved['bash'].version, '5.2.015-1')
@@ -60,7 +60,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['python'], [idx])
+		result = resolver_t.resolve_specs(['python'], [idx])
 
 		self.assertIn('python', result.resolved)
 		self.assertIn('glibc', result.resolved)
@@ -75,7 +75,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['a'], [idx])
+		result = resolver_t.resolve_specs(['a'], [idx])
 
 		self.assertEqual(len(result.resolved), 3)
 		self.assertIn('a', result.resolved)
@@ -91,7 +91,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['python'], [idx])
+		result = resolver_t.resolve_specs(['python'], [idx])
 
 		self.assertIn('glibc', result.resolved)
 
@@ -104,7 +104,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['python'], [idx])
+		result = resolver_t.resolve_specs(['python'], [idx])
 		self.assertGreater(len(result.problems), 0)
 
 	def test_resolve_not_found(self) -> None:
@@ -115,7 +115,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['nonexistent'], [idx])
+		result = resolver_t.resolve_specs(['nonexistent'], [idx])
 		self.assertGreater(len(result.problems), 0)
 		self.assertTrue(any('nonexistent' in p for p in result.problems))
 
@@ -129,7 +129,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['bash', 'python', 'gcc'], [idx])
+		result = resolver_t.resolve_specs(['bash', 'python', 'gcc'], [idx])
 
 		self.assertEqual(len(result.resolved), 3)
 
@@ -143,7 +143,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['python', 'bash'], [idx])
+		result = resolver_t.resolve_specs(['python', 'bash'], [idx])
 
 		self.assertEqual(len(result.resolved), 3)
 		self.assertEqual(result.resolution_order.count('glibc'), 1)
@@ -162,7 +162,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['python'], [extra, core])
+		result = resolver_t.resolve_specs(['python'], [extra, core])
 
 		self.assertIn('python', result.resolved)
 		self.assertIn('glibc', result.resolved)
@@ -181,7 +181,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['bash'], [core, extra])
+		result = resolver_t.resolve_specs(['bash'], [core, extra])
 
 		self.assertEqual(result.resolved['bash'].version, '5.2.015-1')
 
@@ -198,7 +198,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['app'], [idx])
+		result = resolver_t.resolve_specs(['app'], [idx])
 
 		self.assertIn('python', result.resolved)
 		self.assertIn('app', result.resolved)
@@ -216,7 +216,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['app'], [idx])
+		result = resolver_t.resolve_specs(['app'], [idx])
 
 		self.assertIn('python', result.resolved)
 
@@ -230,11 +230,11 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['app'], [idx])
+		result = resolver_t.resolve_specs(['app'], [idx])
 		self.assertGreater(len(result.problems), 0)
 		self.assertTrue(any('conflict' in p for p in result.problems))
 
-	def test_resolve_skip_installed(self) -> None:
+	def test_resolve_skip_via_ignore(self) -> None:
 		idx = self._make_index(
 			'core',
 			[
@@ -242,10 +242,9 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(
-			['python'],
+		result = resolver_t.resolve_specs(
+			['python', '-glibc'],
 			[idx],
-			skip_installed={'glibc'},
 		)
 
 		self.assertIn('python', result.resolved)
@@ -259,7 +258,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve([], [idx])
+		result = resolver_t.resolve_specs([], [idx])
 
 		self.assertEqual(len(result.resolved), 0)
 		self.assertEqual(result.resolution_order, [])
@@ -273,7 +272,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['a'], [idx])
+		result = resolver_t.resolve_specs(['a'], [idx])
 
 		self.assertIn('a', result.resolved)
 		self.assertIn('b', result.resolved)
@@ -289,7 +288,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['app'], [idx])
+		result = resolver_t.resolve_specs(['app'], [idx])
 
 		self.assertEqual(len(result.resolved), 4)
 		self.assertEqual(result.resolution_order.count('libcommon'), 1)
@@ -302,7 +301,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['bash>=5.0'], [idx])
+		result = resolver_t.resolve_specs(['bash>=5.0'], [idx])
 
 		self.assertIn('bash', result.resolved)
 
@@ -314,7 +313,7 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['bash==5.2.015-1'], [idx])
+		result = resolver_t.resolve_specs(['bash==5.2.015-1'], [idx])
 
 		self.assertIn('bash', result.resolved)
 
@@ -326,9 +325,43 @@ class TestResolver(unittest.TestCase):
 			],
 		)
 
-		result = resolver_t.resolve(['bash==5.1.000-1'], [idx])
+		result = resolver_t.resolve_specs(['bash==5.1.000-1'], [idx])
 		self.assertGreater(len(result.problems), 0)
 
+	def test_exclude_package(self) -> None:
+		idx = self._make_index(
+			'core',
+			[
+				self._pkg(name='app', version='1.0', depends=['foo']),
+				self._pkg(name='foo', version='1.0-1'),
+				self._pkg(name='bar', version='1.0-1'),
+			],
+		)
+
+		result = resolver_t.resolve_specs(['app', 'bar', '!bar'], [idx])
+		self.assertIn('app', result.resolved)
+		self.assertIn('foo', result.resolved)
+		self.assertNotIn('bar', result.resolved)
+
+	def test_exclude_transitive_dep(self) -> None:
+		idx = self._make_index(
+			'extra',
+			[
+				self._pkg(name='qpwgraph', version='1.0.0-1', depends=['libgcc']),
+				self._pkg(name='qpwgraph', version='0.8.1-1', depends=['gcc-libs']),
+				self._pkg(name='libgcc', version='15.2.1-1'),
+				self._pkg(name='gcc-libs', version='15.1.1-1'),
+			],
+		)
+
+		# without exclusion, picks latest qpwgraph which needs libgcc
+		result_no_excl = resolver_t.resolve_specs(['qpwgraph'], [idx])
+		self.assertIn('qpwgraph', result_no_excl.resolved)
+
+		# with !libgcc, should pick older qpwgraph or fail
+		result = resolver_t.resolve_specs(['qpwgraph', '!libgcc'], [idx])
+		self.assertNotIn('libgcc', result.resolved)
+
 	def test_error_not_found_message(self) -> None:
 		err = resolver_t.error_t.not_found_t('missing-pkg')
 		self.assertIn('missing-pkg', str(err))

python/online/fxreader/pr34/commands_typed/archlinux/tests/test_solv_backend.py

@@ -100,6 +100,95 @@ class TestSolvPoolUnit(unittest.TestCase):
 		self.assertIn('glibc', result.resolved)
 		self.assertEqual(len(result.problems), 0)
 
+	def test_resolve_less_than_constraint(self) -> None:
+		"""qpwgraph<0.9 should NOT resolve to 1.0.0."""
+		idx = solv_index_t(name='extra')
+		idx.add(solv_package_t(name='qpwgraph', version='0.8.0-1', arch='x86_64'))
+		idx.add(solv_package_t(name='qpwgraph', version='1.0.0-1', arch='x86_64'))
+		idx.build_provides_index()
+
+		pool = solv_pool_t(stores=[repo_store_t(index=idx)])
+		result = pool.resolve(['qpwgraph<0.9'])
+		self.assertIn('qpwgraph', result.resolved)
+		self.assertEqual(result.resolved['qpwgraph'].evr, '0.8.0-1')
+		self.assertEqual(len(result.problems), 0)
+
+	def test_resolve_less_equal_constraint(self) -> None:
+		idx = solv_index_t(name='extra')
+		idx.add(solv_package_t(name='foo', version='1.0-1', arch='x86_64'))
+		idx.add(solv_package_t(name='foo', version='2.0-1', arch='x86_64'))
+		idx.add(solv_package_t(name='foo', version='3.0-1', arch='x86_64'))
+		idx.build_provides_index()
+
+		pool = solv_pool_t(stores=[repo_store_t(index=idx)])
+		result = pool.resolve(['foo<=2.0-1'])
+		self.assertIn('foo', result.resolved)
+		self.assertIn(result.resolved['foo'].evr, ['1.0-1', '2.0-1'])
+		self.assertNotEqual(result.resolved['foo'].evr, '3.0-1')
+
+	def test_resolve_greater_equal_constraint(self) -> None:
+		idx = solv_index_t(name='extra')
+		idx.add(solv_package_t(name='bar', version='1.0-1', arch='x86_64'))
+		idx.add(solv_package_t(name='bar', version='2.0-1', arch='x86_64'))
+		idx.add(solv_package_t(name='bar', version='3.0-1', arch='x86_64'))
+		idx.build_provides_index()
+
+		pool = solv_pool_t(stores=[repo_store_t(index=idx)])
+		result = pool.resolve(['bar>=2.0-1'])
+		self.assertIn('bar', result.resolved)
+		self.assertIn(result.resolved['bar'].evr, ['2.0-1', '3.0-1'])
+		self.assertNotEqual(result.resolved['bar'].evr, '1.0-1')
+
+	def test_resolve_constraint_no_match(self) -> None:
+		idx = solv_index_t(name='extra')
+		idx.add(solv_package_t(name='baz', version='5.0-1', arch='x86_64'))
+		idx.build_provides_index()
+
+		pool = solv_pool_t(stores=[repo_store_t(index=idx)])
+		result = pool.resolve(['baz<1.0'])
+		self.assertNotIn('baz', result.resolved)
+		self.assertGreater(len(result.problems), 0)
+
+	def test_exclude_package(self) -> None:
+		"""!libgcc should prevent libgcc from being resolved."""
+		idx = solv_index_t(name='extra')
+		idx.add(solv_package_t(name='qpwgraph', version='1.0.0-1', arch='x86_64', depends=['libgcc']))
+		idx.add(solv_package_t(name='qpwgraph', version='0.8.1-1', arch='x86_64', depends=['gcc-libs']))
+		idx.add(solv_package_t(name='libgcc', version='15.2.1-1', arch='x86_64'))
+		idx.add(solv_package_t(name='gcc-libs', version='15.1.1-1', arch='x86_64'))
+		idx.build_provides_index()
+
+		pool = solv_pool_t(stores=[repo_store_t(index=idx)])
+		result = pool.resolve(['qpwgraph', '!libgcc'])
+		self.assertIn('qpwgraph', result.resolved)
+		self.assertNotIn('libgcc', result.resolved)
+		# should pick 0.8.1 which depends on gcc-libs, not libgcc
+		self.assertEqual(result.resolved['qpwgraph'].evr, '0.8.1-1')
+		self.assertIn('gcc-libs', result.resolved)
+
+	def test_exclude_multiple(self) -> None:
+		idx = solv_index_t(name='test')
+		idx.add(solv_package_t(name='app', version='1.0-1', arch='x86_64', depends=['foo']))
+		idx.add(solv_package_t(name='foo', version='1.0-1', arch='x86_64'))
+		idx.add(solv_package_t(name='bar', version='1.0-1', arch='x86_64'))
+		idx.build_provides_index()
+
+		pool = solv_pool_t(stores=[repo_store_t(index=idx)])
+		result = pool.resolve(['app', 'bar', '!bar'])
+		self.assertIn('app', result.resolved)
+		self.assertNotIn('bar', result.resolved)
+
+	def test_exclude_only(self) -> None:
+		"""Just exclusions, no packages to install."""
+		idx = solv_index_t(name='test')
+		idx.add(solv_package_t(name='foo', version='1.0-1', arch='x86_64'))
+		idx.build_provides_index()
+
+		pool = solv_pool_t(stores=[repo_store_t(index=idx)])
+		result = pool.resolve(['!foo'])
+		self.assertNotIn('foo', result.resolved)
+		self.assertEqual(len(result.problems), 0)
+
 	def test_resolve_multiple_repos(self) -> None:
 		core = solv_index_t(name='core')
 		core.add(solv_package_t(name='glibc', version='2.38-1', arch='x86_64'))