Datasets:

CrossSWE
/

CrossSWE-Bench

"""Restore an exact, hash-bound Docker build context into a new directory."""
import argparse
from contextlib import contextmanager
import hashlib
import json
from pathlib import Path, PurePosixPath
import shutil
import tarfile
import tempfile


def digest(path):
    value = hashlib.sha256()
    with Path(path).open('rb') as stream:
        for block in iter(lambda: stream.read(1024 * 1024), b''):
            value.update(block)
    return value.hexdigest()


def relative(name):
    path = PurePosixPath(name)
    if (not name or path.is_absolute() or '..' in path.parts or '.' in name.split('/')
            or '\\' in name or str(path) != name):
        raise ValueError('Unsafe context member: ' + name)
    return path


def declared_container_links(manifest, entries, tar):
    """Allow only exact Git-bound links to a declared paired container checkout."""
    absolute = {name: row for name, row in entries.items()
                if row.get('kind') == 'symlink' and PurePosixPath(row['target']).is_absolute()}
    if not absolute:
        return {}
    if manifest.get('schema_version', 1) < 3 or 'instance.json' not in entries:
        raise ValueError('Absolute source link requires a version 3 instance binding')
    member = tar.getmember('instance.json'); row = entries['instance.json']
    if not member.isfile() or member.size != row['bytes'] or member.size > 2 * 1024 * 1024:
        raise ValueError('Invalid source link declaration')
    data = tar.extractfile(member).read()
    if hashlib.sha256(data).hexdigest() != row['sha256']:
        raise ValueError('Source link declaration hash mismatch')
    instance = json.loads(data)
    repositories = {r['key']: r for r in instance['repositories']}
    allowed = {}
    for repo in repositories.values():
        path = PurePosixPath(repo['path'])
        if not path.is_absolute() or path.parts[:2] != ('/', 'testbed') or '..' in path.parts or '.git' in path.parts:
            raise ValueError('Invalid declared repository path')
        for link in repo.get('workspace_links', []):
            target = repositories[link['target_repository']]['path']
            if target == repo['path'] or link['original_target'] != target:
                raise ValueError('Container link does not bind a distinct paired repository')
            blob = target.encode()
            oid = hashlib.sha1(b'blob ' + str(len(blob)).encode() + b'\0' + blob).hexdigest()
            if oid != link['expected_blob']:
                raise ValueError('Container link differs from its original Git blob')
            name = str(PurePosixPath(repo['path'].lstrip('/')) / relative(link['path']))
            if name in allowed:
                raise ValueError('Duplicate container link declaration')
            allowed[name] = target
    if any(allowed.get(name) != row['target'] for name, row in absolute.items()):
        raise ValueError('Undeclared absolute context link')
    return {name: row['target'].lstrip('/') for name, row in absolute.items()}


def check_virtual_links(entries, container_links):
    """Resolve link graphs without touching an absolute container path on the host."""
    links = {name: row['target'] for name, row in entries.items() if row.get('kind') == 'symlink'}
    for name in links:
        pending = list(PurePosixPath(name).parts); stack = []; followed = 0
        while pending:
            part = pending.pop(0)
            if part in ('', '.'):
                continue
            if part == '..':
                if not stack:
                    raise ValueError('Context link escapes output')
                stack.pop(); continue
            stack.append(part); prefix = '/'.join(stack)
            if prefix in links:
                followed += 1
                if followed > 40:
                    raise ValueError('Cyclic or excessive context link graph')
                target = links[prefix]
                if PurePosixPath(target).is_absolute():
                    if prefix not in container_links:
                        raise ValueError('Undeclared absolute context link')
                    stack = []; target = container_links[prefix]
                else:
                    stack.pop()
                pending = list(PurePosixPath(target).parts) + pending


@contextmanager
def archive_stream(root, reference):
    parts=reference.get('parts')
    if parts is not None:
        if not isinstance(parts,list) or not parts:
            raise ValueError('Archive parts must be nonempty')
        with tempfile.TemporaryFile() as output:
            total=0;whole=hashlib.sha256()
            for part in parts:
                source=root/relative(part['path'])
                if source.is_symlink() or part['offset']!=total or source.stat().st_size!=part['bytes']:
                    raise ValueError('Archive part path/order/size mismatch')
                actual=hashlib.sha256()
                with source.open('rb') as stream:
                    for block in iter(lambda:stream.read(1024*1024),b''):
                        actual.update(block);whole.update(block);output.write(block);total+=len(block)
                if actual.hexdigest()!=part['sha256']:
                    raise ValueError('Archive part hash mismatch')
            if total!=reference['bytes'] or whole.hexdigest()!=reference['sha256']:
                raise ValueError('Reconstructed archive hash/size mismatch')
            output.seek(0)
            yield output
    else:
        source=root/relative(reference['path'])
        if source.is_symlink() or source.stat().st_size!=reference['bytes'] or digest(source)!=reference['sha256']:
            raise ValueError('Context archive hash/size mismatch')
        with source.open('rb') as stream:yield stream


def materialize(manifest_path, output, verify_only=False):
    manifest_path, output = Path(manifest_path), Path(output) if output is not None else None
    if output is not None and (output.exists() or output.is_symlink()):
        raise FileExistsError(output)
    manifest = json.loads(manifest_path.read_text())
    reference = manifest['archive']
    entries = {str(relative(row['path'])): row for row in manifest['files']}
    if len(entries) != len(manifest['files']):
        raise ValueError('Duplicate manifest members')
    for name in entries:
        if any(str(parent) in entries for parent in PurePosixPath(name).parents):
            raise ValueError('File/directory context collision')
    with archive_stream(manifest_path.parent,reference) as source, tarfile.open(fileobj=source,mode='r:gz') as tar:
        members = tar.getmembers()
        names = [str(relative(member.name)) for member in members]
        if len(names) != len(set(names)) or set(names) != set(entries):
            raise ValueError('Unlisted, missing or duplicate archive members')
        container_links = declared_container_links(manifest, entries, tar)
        for member in members:
            row = entries[member.name]
            if member.mode != row['mode'] or not 0 <= member.mode <= 0o777:
                raise ValueError('Context member type/size/mode mismatch')
            if row.get('kind','file')=='symlink':
                target=row['target']
                if (not member.issym() or member.linkname!=target or not target
                        or (PurePosixPath(target).is_absolute() and member.name not in container_links)
                        or '\\' in target or '\x00' in target):
                    raise ValueError('Unsafe or changed context link')
                data=target.encode()
                if len(data)!=row['bytes']:
                    raise ValueError('Context link size mismatch')
                actual=hashlib.sha256(data).hexdigest()
            elif row.get('kind','file')=='file' and member.isfile() and member.size==row['bytes']:
                actual_hash=hashlib.sha256()
                with tar.extractfile(member) as stream:
                    for block in iter(lambda:stream.read(1024*1024),b''):actual_hash.update(block)
                actual=actual_hash.hexdigest()
            else:
                raise ValueError('Unsupported or changed context member')
            if actual != row['sha256']:
                raise ValueError('Context member hash mismatch: ' + member.name)
        check_virtual_links(entries, container_links)
        if verify_only:
            return {'files':len(entries),'archive_sha256':reference['sha256'],'state':'ARCHIVE_VERIFIED'}
        output.mkdir(parents=True, exist_ok=False)
        try:
            for member in members:(output/member.name).parent.mkdir(parents=True,exist_ok=True)
            for member in members:
                if member.isfile():
                    target=output/member.name
                    with tar.extractfile(member) as source,target.open('xb') as destination:shutil.copyfileobj(source,destination)
                    target.chmod(member.mode)
            # No regular-file write occurs after creating any source link.
            for member in members:
                if member.issym():(output/member.name).symlink_to(member.linkname)
        except BaseException:
            shutil.rmtree(output)
            raise
    return {'files': len(entries), 'symlinks':sum(row.get('kind')=='symlink' for row in entries.values()),
            'declared_container_symlinks': len(container_links), 'archive_sha256': reference['sha256'], 'output': str(output)}



# crossswe repair publication context compatibility v1
def descriptor_ref(folder, reference):
    path = folder / relative(reference['path'])
    if any(p.is_symlink() for p in (path, *path.parents)) or not path.is_file():
        raise ValueError('Unsafe descriptor reference')
    if path.stat().st_size != reference['bytes'] or digest(path) != reference['sha256']:
        raise ValueError('Descriptor reference hash/size mismatch')
    return path


def current_context(root, instance_id):
    folder = root / 'environments' / relative(instance_id)
    image_path = folder / 'image.json'
    if any(p.is_symlink() for p in (image_path, *image_path.parents)):
        raise ValueError('Unsafe image descriptor path')
    image = json.loads(image_path.read_text())
    if image['instance_id'] != instance_id:
        raise ValueError('Image descriptor instance differs')
    manifest = descriptor_ref(folder, image['context_manifest'])
    recipe = None
    if image.get('recipe'):
        recipe = json.loads(descriptor_ref(folder, image['recipe']).read_text())
        import re
        if (recipe.get('kind') != 'immutable-parent-delta'
                or not re.fullmatch(r'[^@\s]+@sha256:[0-9a-f]{64}', recipe.get('parent_image_ref', ''))
                or recipe['actual_context'] != image['context_manifest']
                or descriptor_ref(folder, recipe['actual_context']) != manifest):
            raise ValueError('Invalid immutable parent/delta recipe')
        parent = json.loads(descriptor_ref(folder, recipe['parent_image_descriptor']).read_text())
        if parent.get('image_ref') != recipe['parent_image_ref']:
            raise ValueError('Recipe parent descriptor identity differs')
        descriptor_ref(folder, parent['context_manifest'])
        descriptor_ref(folder, recipe['source_authority'])
        descriptor_ref(folder, recipe['build_receipt'])
    # Every parent descriptor uses environment-root-relative refs, including an
    # exact historical descriptor stored below history/. Never rebase its refs
    # to the history directory.
    recipe_chain(folder, image)
    return manifest, recipe


def recipe_chain(folder, image, seen=None):
    seen = set() if seen is None else seen
    identity = image['image_ref']
    if identity in seen or len(seen) >= 40:
        raise ValueError('Cyclic or excessive recipe chain')
    seen.add(identity)
    if image.get('provenance_only'):
        if image.get('registry_digest') != 'sha256:e6c20a1727d4eb758737a9c2710a2e0a805bc534fc056929d7ddb2279b55437c' or identity != 'silinchen0617/crossrepo-bench@sha256:e6c20a1727d4eb758737a9c2710a2e0a805bc534fc056929d7ddb2279b55437c':
            raise ValueError('Unsupported provenance-only immutable parent')
        context = descriptor_ref(folder, image['context_manifest'])
        for reference in image['verified_provenance'].values():
            descriptor_ref(folder, reference)
        original = json.loads(descriptor_ref(folder, image['original_descriptor']).read_text())
        if original['registry_digest'] != 'sha256:dd0cf3223f7e9524c4c21aafce54a1b59a7e53288027a1332ddeb1577cad6dda':
            raise ValueError('Historical original parent differs')
        return [{'image_ref': identity, 'context_manifest': str(context), 'context_kind': 'verified-registry-parent-reference'}] + recipe_chain(folder, original, seen)
    context = descriptor_ref(folder, image['context_manifest'])
    result = [{'image_ref': identity, 'context_manifest': str(context),
               'context_kind': 'delta' if image.get('recipe') else 'full'}]
    if image.get('recipe'):
        recipe = json.loads(descriptor_ref(folder, image['recipe']).read_text())
        parent = json.loads(descriptor_ref(folder, recipe['parent_image_descriptor']).read_text())
        if parent['image_ref'] != recipe['parent_image_ref'] or recipe['actual_context'] != image['context_manifest']:
            raise ValueError('Recipe chain identity differs')
        result.extend(recipe_chain(folder, parent, seen))
    return result


def verify_manifest(manifest_path):
    return materialize(manifest_path, None, verify_only=True)


def materialize_image(root, instance_id, output):
    manifest, recipe = current_context(Path(root), instance_id)
    result = materialize(manifest, output)
    result['context_manifest'] = str(manifest)
    result['context_kind'] = 'delta' if recipe else 'full'
    if recipe:
        result['parent_image_ref'] = recipe['parent_image_ref']
        result['source_authority_full_build_context'] = recipe['source_authority_full_build_context']
        result['recipe_note'] = 'Build this actual delta with its pinned parent; historical full context remains preserved.'
    return result


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('--instance-id', required=True)
    parser.add_argument('--output-dir', type=Path, required=True)
    args = parser.parse_args()
    if Path(args.instance_id).name != args.instance_id or args.instance_id in ('','.', '..'):
        parser.error('Use a canonical instance ID')
    root = Path(__file__).resolve().parents[1]
    print(json.dumps(materialize_image(root, args.instance_id, args.output_dir)))


if __name__ == '__main__':
    main()

	"""Restore an exact, hash-bound Docker build context into a new directory."""
	import argparse
	from contextlib import contextmanager
	import hashlib
	import json
	from pathlib import Path, PurePosixPath
	import shutil
	import tarfile
	import tempfile


	def digest(path):
	value = hashlib.sha256()
	with Path(path).open('rb') as stream:
	for block in iter(lambda: stream.read(1024 * 1024), b''):
	value.update(block)
	return value.hexdigest()


	def relative(name):
	path = PurePosixPath(name)
	if (not name or path.is_absolute() or '..' in path.parts or '.' in name.split('/')
	or '\\' in name or str(path) != name):
	raise ValueError('Unsafe context member: ' + name)
	return path


	def declared_container_links(manifest, entries, tar):
	"""Allow only exact Git-bound links to a declared paired container checkout."""
	absolute = {name: row for name, row in entries.items()
	if row.get('kind') == 'symlink' and PurePosixPath(row['target']).is_absolute()}
	if not absolute:
	return {}
	if manifest.get('schema_version', 1) < 3 or 'instance.json' not in entries:
	raise ValueError('Absolute source link requires a version 3 instance binding')
	member = tar.getmember('instance.json'); row = entries['instance.json']
	if not member.isfile() or member.size != row['bytes'] or member.size > 2 * 1024 * 1024:
	raise ValueError('Invalid source link declaration')
	data = tar.extractfile(member).read()
	if hashlib.sha256(data).hexdigest() != row['sha256']:
	raise ValueError('Source link declaration hash mismatch')
	instance = json.loads(data)
	repositories = {r['key']: r for r in instance['repositories']}
	allowed = {}
	for repo in repositories.values():
	path = PurePosixPath(repo['path'])
	if not path.is_absolute() or path.parts[:2] != ('/', 'testbed') or '..' in path.parts or '.git' in path.parts:
	raise ValueError('Invalid declared repository path')
	for link in repo.get('workspace_links', []):
	target = repositories[link['target_repository']]['path']
	if target == repo['path'] or link['original_target'] != target:
	raise ValueError('Container link does not bind a distinct paired repository')
	blob = target.encode()
	oid = hashlib.sha1(b'blob ' + str(len(blob)).encode() + b'\0' + blob).hexdigest()
	if oid != link['expected_blob']:
	raise ValueError('Container link differs from its original Git blob')
	name = str(PurePosixPath(repo['path'].lstrip('/')) / relative(link['path']))
	if name in allowed:
	raise ValueError('Duplicate container link declaration')
	allowed[name] = target
	if any(allowed.get(name) != row['target'] for name, row in absolute.items()):
	raise ValueError('Undeclared absolute context link')
	return {name: row['target'].lstrip('/') for name, row in absolute.items()}


	def check_virtual_links(entries, container_links):
	"""Resolve link graphs without touching an absolute container path on the host."""
	links = {name: row['target'] for name, row in entries.items() if row.get('kind') == 'symlink'}
	for name in links:
	pending = list(PurePosixPath(name).parts); stack = []; followed = 0
	while pending:
	part = pending.pop(0)
	if part in ('', '.'):
	continue
	if part == '..':
	if not stack:
	raise ValueError('Context link escapes output')
	stack.pop(); continue
	stack.append(part); prefix = '/'.join(stack)
	if prefix in links:
	followed += 1
	if followed > 40:
	raise ValueError('Cyclic or excessive context link graph')
	target = links[prefix]
	if PurePosixPath(target).is_absolute():
	if prefix not in container_links:
	raise ValueError('Undeclared absolute context link')
	stack = []; target = container_links[prefix]
	else:
	stack.pop()
	pending = list(PurePosixPath(target).parts) + pending


	@contextmanager
	def archive_stream(root, reference):
	parts=reference.get('parts')
	if parts is not None:
	if not isinstance(parts,list) or not parts:
	raise ValueError('Archive parts must be nonempty')
	with tempfile.TemporaryFile() as output:
	total=0;whole=hashlib.sha256()
	for part in parts:
	source=root/relative(part['path'])
	if source.is_symlink() or part['offset']!=total or source.stat().st_size!=part['bytes']:
	raise ValueError('Archive part path/order/size mismatch')
	actual=hashlib.sha256()
	with source.open('rb') as stream:
	for block in iter(lambda:stream.read(1024*1024),b''):
	actual.update(block);whole.update(block);output.write(block);total+=len(block)
	if actual.hexdigest()!=part['sha256']:
	raise ValueError('Archive part hash mismatch')
	if total!=reference['bytes'] or whole.hexdigest()!=reference['sha256']:
	raise ValueError('Reconstructed archive hash/size mismatch')
	output.seek(0)
	yield output
	else:
	source=root/relative(reference['path'])
	if source.is_symlink() or source.stat().st_size!=reference['bytes'] or digest(source)!=reference['sha256']:
	raise ValueError('Context archive hash/size mismatch')
	with source.open('rb') as stream:yield stream


	def materialize(manifest_path, output, verify_only=False):
	manifest_path, output = Path(manifest_path), Path(output) if output is not None else None
	if output is not None and (output.exists() or output.is_symlink()):
	raise FileExistsError(output)
	manifest = json.loads(manifest_path.read_text())
	reference = manifest['archive']
	entries = {str(relative(row['path'])): row for row in manifest['files']}
	if len(entries) != len(manifest['files']):
	raise ValueError('Duplicate manifest members')
	for name in entries:
	if any(str(parent) in entries for parent in PurePosixPath(name).parents):
	raise ValueError('File/directory context collision')
	with archive_stream(manifest_path.parent,reference) as source, tarfile.open(fileobj=source,mode='r:gz') as tar:
	members = tar.getmembers()
	names = [str(relative(member.name)) for member in members]
	if len(names) != len(set(names)) or set(names) != set(entries):
	raise ValueError('Unlisted, missing or duplicate archive members')
	container_links = declared_container_links(manifest, entries, tar)
	for member in members:
	row = entries[member.name]
	if member.mode != row['mode'] or not 0 <= member.mode <= 0o777:
	raise ValueError('Context member type/size/mode mismatch')
	if row.get('kind','file')=='symlink':
	target=row['target']
	if (not member.issym() or member.linkname!=target or not target
	or (PurePosixPath(target).is_absolute() and member.name not in container_links)
	or '\\' in target or '\x00' in target):
	raise ValueError('Unsafe or changed context link')
	data=target.encode()
	if len(data)!=row['bytes']:
	raise ValueError('Context link size mismatch')
	actual=hashlib.sha256(data).hexdigest()
	elif row.get('kind','file')=='file' and member.isfile() and member.size==row['bytes']:
	actual_hash=hashlib.sha256()
	with tar.extractfile(member) as stream:
	for block in iter(lambda:stream.read(1024*1024),b''):actual_hash.update(block)
	actual=actual_hash.hexdigest()
	else:
	raise ValueError('Unsupported or changed context member')
	if actual != row['sha256']:
	raise ValueError('Context member hash mismatch: ' + member.name)
	check_virtual_links(entries, container_links)
	if verify_only:
	return {'files':len(entries),'archive_sha256':reference['sha256'],'state':'ARCHIVE_VERIFIED'}
	output.mkdir(parents=True, exist_ok=False)
	try:
	for member in members:(output/member.name).parent.mkdir(parents=True,exist_ok=True)
	for member in members:
	if member.isfile():
	target=output/member.name
	with tar.extractfile(member) as source,target.open('xb') as destination:shutil.copyfileobj(source,destination)
	target.chmod(member.mode)
	# No regular-file write occurs after creating any source link.
	for member in members:
	if member.issym():(output/member.name).symlink_to(member.linkname)
	except BaseException:
	shutil.rmtree(output)
	raise
	return {'files': len(entries), 'symlinks':sum(row.get('kind')=='symlink' for row in entries.values()),
	'declared_container_symlinks': len(container_links), 'archive_sha256': reference['sha256'], 'output': str(output)}



	# crossswe repair publication context compatibility v1
	def descriptor_ref(folder, reference):
	path = folder / relative(reference['path'])
	if any(p.is_symlink() for p in (path, *path.parents)) or not path.is_file():
	raise ValueError('Unsafe descriptor reference')
	if path.stat().st_size != reference['bytes'] or digest(path) != reference['sha256']:
	raise ValueError('Descriptor reference hash/size mismatch')
	return path


	def current_context(root, instance_id):
	folder = root / 'environments' / relative(instance_id)
	image_path = folder / 'image.json'
	if any(p.is_symlink() for p in (image_path, *image_path.parents)):
	raise ValueError('Unsafe image descriptor path')
	image = json.loads(image_path.read_text())
	if image['instance_id'] != instance_id:
	raise ValueError('Image descriptor instance differs')
	manifest = descriptor_ref(folder, image['context_manifest'])
	recipe = None
	if image.get('recipe'):
	recipe = json.loads(descriptor_ref(folder, image['recipe']).read_text())
	import re
	if (recipe.get('kind') != 'immutable-parent-delta'
	or not re.fullmatch(r'[^@\s]+@sha256:[0-9a-f]{64}', recipe.get('parent_image_ref', ''))
	or recipe['actual_context'] != image['context_manifest']
	or descriptor_ref(folder, recipe['actual_context']) != manifest):
	raise ValueError('Invalid immutable parent/delta recipe')
	parent = json.loads(descriptor_ref(folder, recipe['parent_image_descriptor']).read_text())
	if parent.get('image_ref') != recipe['parent_image_ref']:
	raise ValueError('Recipe parent descriptor identity differs')
	descriptor_ref(folder, parent['context_manifest'])
	descriptor_ref(folder, recipe['source_authority'])
	descriptor_ref(folder, recipe['build_receipt'])
	# Every parent descriptor uses environment-root-relative refs, including an
	# exact historical descriptor stored below history/. Never rebase its refs
	# to the history directory.
	recipe_chain(folder, image)
	return manifest, recipe


	def recipe_chain(folder, image, seen=None):
	seen = set() if seen is None else seen
	identity = image['image_ref']
	if identity in seen or len(seen) >= 40:
	raise ValueError('Cyclic or excessive recipe chain')
	seen.add(identity)
	if image.get('provenance_only'):
	if image.get('registry_digest') != 'sha256:e6c20a1727d4eb758737a9c2710a2e0a805bc534fc056929d7ddb2279b55437c' or identity != 'silinchen0617/crossrepo-bench@sha256:e6c20a1727d4eb758737a9c2710a2e0a805bc534fc056929d7ddb2279b55437c':
	raise ValueError('Unsupported provenance-only immutable parent')
	context = descriptor_ref(folder, image['context_manifest'])
	for reference in image['verified_provenance'].values():
	descriptor_ref(folder, reference)
	original = json.loads(descriptor_ref(folder, image['original_descriptor']).read_text())
	if original['registry_digest'] != 'sha256:dd0cf3223f7e9524c4c21aafce54a1b59a7e53288027a1332ddeb1577cad6dda':
	raise ValueError('Historical original parent differs')
	return [{'image_ref': identity, 'context_manifest': str(context), 'context_kind': 'verified-registry-parent-reference'}] + recipe_chain(folder, original, seen)
	context = descriptor_ref(folder, image['context_manifest'])
	result = [{'image_ref': identity, 'context_manifest': str(context),
	'context_kind': 'delta' if image.get('recipe') else 'full'}]
	if image.get('recipe'):
	recipe = json.loads(descriptor_ref(folder, image['recipe']).read_text())
	parent = json.loads(descriptor_ref(folder, recipe['parent_image_descriptor']).read_text())
	if parent['image_ref'] != recipe['parent_image_ref'] or recipe['actual_context'] != image['context_manifest']:
	raise ValueError('Recipe chain identity differs')
	result.extend(recipe_chain(folder, parent, seen))
	return result


	def verify_manifest(manifest_path):
	return materialize(manifest_path, None, verify_only=True)


	def materialize_image(root, instance_id, output):
	manifest, recipe = current_context(Path(root), instance_id)
	result = materialize(manifest, output)
	result['context_manifest'] = str(manifest)
	result['context_kind'] = 'delta' if recipe else 'full'
	if recipe:
	result['parent_image_ref'] = recipe['parent_image_ref']
	result['source_authority_full_build_context'] = recipe['source_authority_full_build_context']
	result['recipe_note'] = 'Build this actual delta with its pinned parent; historical full context remains preserved.'
	return result


	def main():
	parser = argparse.ArgumentParser(description=__doc__)
	parser.add_argument('--instance-id', required=True)
	parser.add_argument('--output-dir', type=Path, required=True)
	args = parser.parse_args()
	if Path(args.instance_id).name != args.instance_id or args.instance_id in ('','.', '..'):
	parser.error('Use a canonical instance ID')
	root = Path(__file__).resolve().parents[1]
	print(json.dumps(materialize_image(root, args.instance_id, args.output_dir)))


	if __name__ == '__main__':
	main()