[Bug 43315] New: Steam fails to start [After update 07/10/2017]

https://bugs.winehq.org/show_bug.cgi?id=43315

Bug ID: 43315
           Summary: Steam fails to start [After update 07/10/2017]
           Product: Wine
           Version: 2.12
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: -unknown
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Following an update received on 07/10/2017, Steam fails to start.

Prefix: 64bit
Version: Wine 2.12 [Also occurs on Wine-staging 2.11]
OS: Arch Linux

No overrides in prefix.
Wine is not the cause of the error.
I started Steam on my Wine-staging 2.11 two days ago, it was fine.
Started Steam today, and it failed following an update to Steam.
Updated Wine to 2.12 (non-staging), and the same error occurs.
In sum, Steam update broke Steam in wine.

Error log:
fixme:ver:GetCurrentPackageId (0x33e470 (nil)): stub
net.cpp (262) : Fatal Assertion Failed: PlatformSocketsInit failed, error [no
name available] (1)
net.cpp (262) : Fatal assert failed: net.cpp, line 262.  Application exiting.

Assert( Fatal Assertion Failed: PlatformSocketsInit failed, error [no name
available] (1) ):net.cpp:262

fixme:ntdll:EtwEventRegister ({47a9201e-73b0-42ce-9821-7e134361bc6f},
0x3f006760, 0x3f041d28, 0x3f041d20) stub.
fixme:ntdll:EtwEventRegister ({58a9201e-73b0-42ce-9821-7e134361bc70},
0x3f006760, 0x3f041d60, 0x3f041d58) stub.
fixme:ntdll:EtwEventRegister ({3fa9201e-73b0-43fe-9821-7e145359bc6f},
0x3f006760, 0x3f041cf0, 0x3f041ce8) stub.
fixme:ntdll:EtwEventRegister ({1432afee-73b0-42ce-9821-7e134361b433},
0x3f006760, 0x3f041d98, 0x3f041d90) stub.
fixme:ntdll:EtwEventRegister ({4372afee-73b0-42ce-9821-7e134361b519},
0x3f006760, 0x3f041dd0, 0x3f041dc8) stub.
fixme:dbghelp:elf_search_auxv can't find symbol in module
_ExitOnFatalAssert