msgpack link failure - non-transitive pragma(lib)?

[TED_996]

I've been trying to debug this for a long time now. I am trying 
to build one of the msgpack examples (examples/upacker_foreach.d) 
and the linking failed. I have since succeeded and I'm trying to 
find out if this is intended behavior or a bug in D (not msgpack, 
I think).

TL;DR: it seems to me like the pragma(lib, "ws2_32"); in 
core.sys.windows.winsock2, imported in msgpack.common, imported 
in msgpack (package.d), imported in my source files, does not 
hold; this was fixed when I added the pragma in my source file 
too.

Versions: Windows 10, dmd 2.080.0, dub 1.9.0

The dub build output:

Performing "debug" build using D:\D\dmd2\windows\bin\dmd.exe for 
x86.
msgpack-d 1.0.0-beta.6: target for configuration "library" is up 
to date.
hw ~master: building configuration "application"...
Linking...

OPTLINK (R) for Win32  Release 8.00.17
Copyright (C) Digital Mars 1989-2013  All rights reserved.
http://www.digitalmars.com/ctg/optlink.html
.dub\build\application-debug-windows-x86-dmd_2080-1E3111031ACEC4AEF53C62127331208A\hw.obj(hw)
  Error 42: Symbol Undefined _ntohl at 4
.dub\build\application-debug-windows-x86-dmd_2080-1E3111031ACEC4AEF53C62127331208A\hw.obj(hw)
  Error 42: Symbol Undefined _ntohs at 4
Error: linker exited with status 2
D:\D\dmd2\windows\bin\dmd.exe failed with exit code 1.

dub.json:

{
	"name": "hw",
	"authors": [
		"ted_996"
	],
	"description": "A minimal D application.",
	"copyright": "Copyright © 2018, ted_996",
	"license": "proprietary",
	"dependencies": {
		"msgpack-d": ">=1.0.0-beta.6"
	}
}

After some digging, I found that other binaries that used msgpack 
(DCD) were importing ws2_32, but it seemed like my binary was 
not. Both debug and release and x86 and x64 versions were failing 
to link; msgpack built fine but probably only the msgpack.lib 
file (no final link).

However, when I (counter-intuitively, for me) added pragma(lib, 
"ws2_32"); to my own source files, it built successfully. Should 
that have been necessary? it was not in any examples. What gives?

Thanks!