can1357/oh-my-pi · error · ArchiveError

Tar directory '${formatArchivePathForError(normalized)}' can

Error message

Tar directory '${formatArchivePathForError(normalized)}' cannot contain file data

What it means

A member whose raw path ends with '/' or '\' is treated as a directory entry, but tar directory entries carry no payload. The encoder throws when such an entry was given non-empty bytes, since there is no valid way to store file data under a directory-typed header.

Source

Thrown at packages/utils/src/ar/tar.ts:749

			directory ? 0x35 : 0x30,
		),
	);
	if (!directory) appendPayload(parts, payload);
}

/** Encode files as a deterministic ustar archive, using PAX records for overflow paths. */
export async function encodeTar(members: Iterable<readonly [string, Uint8Array]>): Promise<Uint8Array> {
	const parts: Uint8Array[] = [];
	const kinds = new Map<string, "directory" | "file">();
	let sequence = 0;
	for (const [rawPath, bytes] of members) {
		const directory = rawPath.endsWith("/") || rawPath.endsWith("\\");
		const normalized = normalizeArchiveEntryPath(rawPath);
		if (!normalized) throw new ArchiveError(`Invalid tar member path '${formatArchivePathForError(rawPath)}'`);
		const pathBytes = TEXT_ENCODER.encode(normalized);
		if (pathBytes.byteLength === 0) throw new ArchiveError("Invalid empty tar member path");
		if (directory && bytes.byteLength !== 0) {
			throw new ArchiveError(`Tar directory '${formatArchivePathForError(normalized)}' cannot contain file data`);
		}
		const segments = normalized.split("/");
		for (let index = 1; index < segments.length; index++) {
			const parent = segments.slice(0, index).join("/");
			const kind = kinds.get(parent);
			if (kind === "file")
				throw new ArchiveError(`Tar member '${formatArchivePathForError(parent)}' is not a directory`);
			if (kind === "directory") continue;
			kinds.set(parent, "directory");
			appendTarEntry(parts, parent, new Uint8Array(0), true, sequence++);
		}
		const existing = kinds.get(normalized);
		if (existing) {
			if (directory && existing === "directory") continue;
			throw new ArchiveError(`Duplicate tar member path '${formatArchivePathForError(normalized)}'`);
		}
		kinds.set(normalized, directory ? "directory" : "file");
		appendTarEntry(parts, normalized, bytes, directory, sequence++);

View on GitHub (pinned to 9690622007)

Solutions

Remove the trailing slash for entries that carry data
Move the bytes under a non-directory key like 'dir/index.txt'
Drop the bytes if the entry is genuinely a directory

Example fix

// before
members.set("docs/", fileBytes);
// after
members.set("docs/readme.txt", fileBytes);

Defensive patterns

Strategy: validation

Validate before calling

for (const [key, bytes] of members) {
	if ((key.endsWith("/") || key.endsWith("\\")) && bytes.byteLength > 0) {
		throw new Error(`'${key}' is a directory but has ${bytes.byteLength} bytes`);
	}
}

Try / catch

try {
	return await createTar(members);
} catch (err) {
	if (err instanceof ArchiveError && err.message.includes("cannot contain file data")) {
		// move data under a non-directory key
	}
	throw err;
}

Prevention

Reserve trailing-slash keys for empty directory entries only
Keep directory and file entries in separate conventions in your data model

When it happens

Trigger: createTar called with a key like 'dir/' mapped to non-empty bytes — e.g. a data structure that stores a folder's concatenated contents under the folder's name with a trailing slash.

Common situations: Converting from zip or a virtual FS where directories are implicit and someone appended '/' to a file key; hand-built members maps mixing file/dir conventions.

Related errors

AI-assisted analysis of can1357/oh-my-pi@9690622007 (2026-08-31). Data as JSON: /api/errors/15bf407938559177. Report an issue: GitHub.