findZigLibDirFromSelfExe

pub fn findZigLibDirFromSelfExe(
    allocator: Allocator,
    io: Io,
    /// The return value of `getResolvedCwd`.
    /// Passed as an argument to avoid pointlessly repeating the call.
    cwd_path: []const u8,
    self_exe_path: []const u8,
) error{ OutOfMemory, FileNotFound }!Cache.Directory {
    const cwd = Dir.cwd();
    var cur_path: []const u8 = self_exe_path;
    while (Dir.path.dirname(cur_path)) |dirname| : (cur_path = dirname) {
        var base_dir = cwd.openDir(io, dirname, .{}) catch continue;
        defer base_dir.close(io);

        const sub_directory = testZigInstallPrefix(io, base_dir) orelse continue;
        const p = try Dir.path.join(allocator, &.{ dirname, sub_directory.path.? });
        defer allocator.free(p);

        const resolved = try resolvePath(allocator, cwd_path, &.{p});
        return .{
            .handle = sub_directory.handle,
            .path = if (resolved.len == 0) null else resolved,
        };
    }
    return error.FileNotFound;
}