FDS/OS 1.0 fixes

tools/prepare-void-workspace

@@ -0,0 +1,125 @@
+#!/usr/bin/env python3
+"""Prepare a writable Void build checkout outside the upstream submodule."""
+import fcntl
+import hashlib
+import os
+from pathlib import Path
+import re
+import shutil
+import subprocess
+import sys
+import tempfile
+
+
+def git(directory, *arguments):
+    return subprocess.check_output(['git', '-C', str(directory), *arguments], text=True).strip()
+
+
+def inventory(root):
+    result = {}
+    for path in sorted(root.rglob('*')):
+        name = path.relative_to(root).as_posix()
+        if path.is_symlink():
+            result[name] = ('link', os.readlink(path))
+        elif path.is_file():
+            with path.open('rb') as stream:
+                result[name] = ('file', path.stat().st_mode & 0o777, hashlib.file_digest(stream, 'sha256').hexdigest())
+        elif path.is_dir():
+            result[name] = ('directory',)
+        else:
+            raise ValueError(f'Unexpected special source file: {path}')
+    return result
+
+
+def prepare(project):
+    source = project / 'vendor/void-packages'
+    workspace = project / '.host/void-packages'
+    pin = (project / 'VOID_PACKAGES_COMMIT').read_text().strip()
+    if not re.fullmatch('[0-9a-f]{40}', pin) or git(source, 'rev-parse', 'HEAD') != pin:
+        raise ValueError('Upstream Void checkout differs from VOID_PACKAGES_COMMIT')
+    if git(source, 'diff', 'HEAD', '--'):
+        raise ValueError('Upstream Void has staged or tracked changes; preserve them outside the submodule first')
+    if source.is_symlink() or workspace.is_symlink():
+        raise ValueError('Void source and build checkout must be real directories')
+
+    # Migrate only known generated copies after comparing every entry. Unknown
+    # or independently edited source files are never deleted or overwritten.
+    overlays = {path.parent.name: path.parent for path in (project / 'packages').glob('*/template')}
+    for name in ('hello', 'report'):
+        example = project / f'examples/software/{name}/void'
+        if (example / 'template').is_file():
+            overlays[f'fds-demo-{name}'] = example
+    moves = []
+    duplicates = []
+    known = set()
+    for package, original in overlays.items():
+        old = source / 'srcpkgs' / package
+        if not old.exists() and not old.is_symlink():
+            continue
+        if git(source, 'ls-tree', 'HEAD', f'srcpkgs/{package}'):
+            raise ValueError(f'FDS overlay collides with upstream package: {package}')
+        if old.is_symlink() or not old.is_dir() or inventory(old) != inventory(original):
+            raise ValueError(f'Preserve independent edits in {old} before migrating it')
+        known.add(f'srcpkgs/{package}/')
+        new = workspace / 'srcpkgs' / package
+        if new.exists() or new.is_symlink():
+            if new.is_symlink() or not new.is_dir() or inventory(new) != inventory(original):
+                raise ValueError(f'Conflicting generated overlay: {new}')
+            duplicates.append(old)
+        else:
+            moves.append((old, new))
+    for name in git(source, 'ls-files', '--others', '--exclude-standard').splitlines():
+        if not any(name.startswith(prefix) for prefix in known):
+            raise ValueError(f'Untracked upstream file must be moved outside the submodule: {name}')
+    for old in [source / 'hostdir', *sorted(source.glob('masterdir-*')), source / 'etc/conf']:
+        if not old.exists() and not old.is_symlink():
+            continue
+        new = workspace / old.relative_to(source)
+        if old.is_symlink() or new.exists() or new.is_symlink():
+            raise ValueError(f'Cannot migrate {old}: symlink or existing destination {new}; reconcile explicitly')
+        if old == source / 'etc/conf' and old.read_bytes() != (project / 'config/xbps-src.conf').read_bytes():
+            raise ValueError('Old Void configuration differs from config/xbps-src.conf; reconcile explicitly')
+        moves.append((old, new))
+
+    if not workspace.exists():
+        # Independent objects keep this cache usable without Git alternates or
+        # hardlinks back into the submodule. No network access is needed.
+        with tempfile.TemporaryDirectory(prefix='void-checkout.', dir=workspace.parent) as temporary:
+            checkout = Path(temporary) / 'checkout'
+            subprocess.run(['git', 'clone', '--quiet', '--no-hardlinks', '--no-checkout', str(source), str(checkout)], check=True)
+            subprocess.run(['git', '-C', str(checkout), 'checkout', '--quiet', '--detach', pin], check=True)
+            subprocess.run(['git', '-C', str(checkout), 'remote', 'remove', 'origin'], check=True)
+            checkout.rename(workspace)
+    else:
+        if not (workspace / '.git').is_dir() or git(workspace, 'diff', 'HEAD', '--'):
+            raise ValueError('Build checkout has tracked changes; preserve them before preparing it')
+        if git(workspace, 'rev-parse', 'HEAD') != pin:
+            subprocess.run(['git', '-C', str(workspace), 'fetch', '--quiet', '--update-shallow', str(source), pin], check=True)
+            # Git refuses an update that would overwrite local files.
+            subprocess.run(['git', '-C', str(workspace), 'checkout', '--quiet', '--detach', pin], check=True)
+    for old, new in moves:
+        new.parent.mkdir(parents=True, exist_ok=True)
+        old.rename(new)
+        print(f'Moved {old.relative_to(project)} to {new.relative_to(project)}', flush=True)
+    for old in duplicates:
+        shutil.rmtree(old)
+    if git(source, 'status', '--porcelain', '--untracked-files=all'):
+        raise ValueError('Upstream submodule is not clean after preparation')
+    print('PASS: clean upstream reference; writable build checkout in .host/void-packages', flush=True)
+
+
+def main():
+    project = Path(__file__).resolve().parents[1]
+    if len(sys.argv) != 1:
+        sys.exit('Usage: tools/prepare-void-workspace')
+    try:
+        (project / '.host').mkdir(exist_ok=True)
+        with (project / '.host/void-workspace.lock').open('a') as lock:
+            fcntl.flock(lock, fcntl.LOCK_EX | fcntl.LOCK_NB)
+            prepare(project)
+    except (OSError, ValueError, subprocess.CalledProcessError) as error:
+        sys.exit(f'ERROR: {error}')
+
+
+if __name__ == '__main__':
+    main()