Issue 1:
C:\Coding3\deno>deno run test/test.js
Compile https://deno.land/std/fs/mod.ts
error: TS2339 [ERROR]: Property 'utime' does not exist on type 'typeof Deno'.
await Deno.utime(dest, statInfo.atime, statInfo.mtime);
~~~~~
at https://deno.land/std/fs/copy.ts:92:16

TS2339 [ERROR]: Property 'utimeSync' does not exist on type 'typeof Deno'.
Deno.utimeSync(dest, statInfo.atime, statInfo.mtime);
~~~~~~~~~
at https://deno.land/std/fs/copy.ts:103:10

TS2339 [ERROR]: Property 'symlink' does not exist on type 'typeof Deno'.
await Deno.symlink(originSrcFilePath, dest, {
~~~~~~~
at https://deno.land/std/fs/copy.ts:117:16

TS2339 [ERROR]: Property 'symlink' does not exist on type 'typeof Deno'.
await Deno.symlink(originSrcFilePath, dest);
~~~~~~~
at https://deno.land/std/fs/copy.ts:121:16

TS2339 [ERROR]: Property 'utime' does not exist on type 'typeof Deno'.
await Deno.utime(dest, statInfo.atime, statInfo.mtime);
~~~~~
at https://deno.land/std/fs/copy.ts:127:16

TS2339 [ERROR]: Property 'symlinkSync' does not exist on type 'typeof Deno'.
Deno.symlinkSync(originSrcFilePath, dest, {
~~~~~~~~~~~
at https://deno.land/std/fs/copy.ts:141:10

TS2339 [ERROR]: Property 'symlinkSync' does not exist on type 'typeof Deno'.
Deno.symlinkSync(originSrcFilePath, dest);
~~~~~~~~~~~
at https://deno.land/std/fs/copy.ts:145:10

TS2339 [ERROR]: Property 'utimeSync' does not exist on type 'typeof Deno'.
Deno.utimeSync(dest, statInfo.atime, statInfo.mtime);
~~~~~~~~~
at https://deno.land/std/fs/copy.ts:152:10

TS2339 [ERROR]: Property 'utime' does not exist on type 'typeof Deno'.
await Deno.utime(dest, srcStatInfo.atime, srcStatInfo.mtime);
~~~~~
at https://deno.land/std/fs/copy.ts:172:16

TS2339 [ERROR]: Property 'utimeSync' does not exist on type 'typeof Deno'.
Deno.utimeSync(dest, srcStatInfo.atime, srcStatInfo.mtime);
~~~~~~~~~
at https://deno.land/std/fs/copy.ts:200:10

TS2339 [ERROR]: Property 'link' does not exist on type 'typeof Deno'.
await Deno.link(src, dest);
~~~~
at https://deno.land/std/fs/ensure_link.ts:28:14

TS2339 [ERROR]: Property 'linkSync' does not exist on type 'typeof Deno'.
Deno.linkSync(src, dest);
~~~~~~~~
at https://deno.land/std/fs/ensure_link.ts:52:8

TS2339 [ERROR]: Property 'symlink' does not exist on type 'typeof Deno'.
await Deno.symlink(src, dest, {
~~~~~~~
at https://deno.land/std/fs/ensure_symlink.ts:33:16

TS2339 [ERROR]: Property 'symlink' does not exist on type 'typeof Deno'.
await Deno.symlink(src, dest);
~~~~~~~
at https://deno.land/std/fs/ensure_symlink.ts:37:16

TS2339 [ERROR]: Property 'symlinkSync' does not exist on type 'typeof Deno'.
Deno.symlinkSync(src, dest, {
~~~~~~~~~~~
at https://deno.land/std/fs/ensure_symlink.ts:65:10

TS2339 [ERROR]: Property 'symlinkSync' does not exist on type 'typeof Deno'.
Deno.symlinkSync(src, dest);
~~~~~~~~~~~
at https://deno.land/std/fs/ensure_symlink.ts:69:10

Found 16 errors.

Code used:

import { exists, existsSync } from "https://deno.land/std/fs/mod.ts";

exists("./foo"); // returns a Promise<boolean>
existsSync("./foo"); // returns boolean

Issue 2:
I'm trying the following script and I get a few errors.

index.ts

import { exists } from "https://deno.land/std/fs/mod.ts";

const found = await exists('/folder');
console.log('Found:', found);

Error:

error TS2339: Property 'utime' does not exist on type 'typeof Deno'.
await Deno.utime(dest, statInfo.atime, statInfo.mtime);
~~~~~
at https://deno.land/std/fs/copy.ts:90:16

error TS2339: Property 'utimeSync' does not exist on type 'typeof Deno'.
Deno.utimeSync(dest, statInfo.atime, statInfo.mtime);
~~~~~~~~~
at https://deno.land/std/fs/copy.ts:101:10

error TS2339: Property 'symlink' does not exist on type 'typeof Deno'.
await Deno.symlink(originSrcFilePath, dest, type);
~~~~~~~
at https://deno.land/std/fs/copy.ts:114:14

error TS2339: Property 'utime' does not exist on type 'typeof Deno'.
await Deno.utime(dest, statInfo.atime, statInfo.mtime);
~~~~~
at https://deno.land/std/fs/copy.ts:119:16

error TS2339: Property 'symlinkSync' does not exist on type 'typeof Deno'.
Deno.symlinkSync(originSrcFilePath, dest, type);
~~~~~~~~~~~
at https://deno.land/std/fs/copy.ts:132:8

error TS2339: Property 'utimeSync' does not exist on type 'typeof Deno'.
Deno.utimeSync(dest, statInfo.atime, statInfo.mtime);
~~~~~~~~~
at https://deno.land/std/fs/copy.ts:137:10

error TS2339: Property 'utime' does not exist on type 'typeof Deno'.
await Deno.utime(dest, srcStatInfo.atime, srcStatInfo.mtime);
~~~~~
at https://deno.land/std/fs/copy.ts:157:16

error TS2339: Property 'utimeSync' does not exist on type 'typeof Deno'.
Deno.utimeSync(dest, srcStatInfo.atime, srcStatInfo.mtime);
~~~~~~~~~
at https://deno.land/std/fs/copy.ts:185:10

error TS2339: Property 'link' does not exist on type 'typeof Deno'.
await Deno.link(src, dest);
~~~~
at https://deno.land/std/fs/ensure_link.ts:28:14

error TS2339: Property 'linkSync' does not exist on type 'typeof Deno'.
Deno.linkSync(src, dest);
~~~~~~~~
at https://deno.land/std/fs/ensure_link.ts:52:8

error TS2339: Property 'symlink' does not exist on type 'typeof Deno'.
await Deno.symlink(src, dest, srcFilePathType);
~~~~~~~
at https://deno.land/std/fs/ensure_symlink.ts:31:14

error TS2339: Property 'symlinkSync' does not exist on type 'typeof Deno'.
Deno.symlinkSync(src, dest, srcFilePathType);
~~~~~~~~~~~
at https://deno.land/std/fs/ensure_symlink.ts:58:8

Found 12 errors.

deno 1.0.0-rc1

v8 8.2.308

typescript 3.8.3