populateOtherManifest

    pub fn populateOtherManifest(man: *Manifest, other: *Manifest, prefix_map: [5]u8) Allocator.Error!void {
        const gpa = other.cache.gpa;
        assert(@typeInfo(std.zig.Server.Message.PathPrefix).@"enum".field_names.len == man.cache.prefixes_len);
        assert(man.cache.prefixes_len == 5);
        for (man.files.keys()) |file| {
            const prefixed_path: PrefixedPath = .{
                .prefix = prefix_map[file.prefixed_path.prefix],
                .sub_path = try gpa.dupe(u8, file.prefixed_path.sub_path),
            };
            errdefer gpa.free(prefixed_path.sub_path);

            const gop = try other.files.getOrPutAdapted(gpa, prefixed_path, FilesAdapter{});
            errdefer _ = other.files.pop();

            if (gop.found_existing) {
                gpa.free(prefixed_path.sub_path);
                continue;
            }

            gop.key_ptr.* = .{
                .prefixed_path = prefixed_path,
                .max_file_size = file.max_file_size,
                .handle = file.handle,
                .stat = file.stat,
                .bin_digest = file.bin_digest,
                .contents = null,
            };

            other.hash.hasher.update(&gop.key_ptr.bin_digest);
        }
    }