Cannot start GmodDS with a custom workshop list

I can launch my gmod dedicated server fine on Archlinux using this

./srcds_run -debug -game garrysmod +maxplayers 32 +gamemode sandbox

But whenever I use this:

./srcds_run -debug -game garrysmod +maxplayers 32 +host_workshop_collection 176635637 -authkey
[Censored] +gamemode sandbox +map ph_Prop_ink

It crashes with the following error:

130 server@xxx ~ % ./                                                                          :(
WARNING: No map specified! Server may not heartbeat.
Auto detecting CPU
Using default binary: ./srcds_linux
Enabling debug mode
Server will auto-restart if there is a crash.

Console initialized.
ConVarRef mat_dxlevel doesn't point to an existing ConVar loaded for "Garry's Mod"
Setting breakpad minidump AppID = 4000
Initializing Steam libraries for secure Internet server
[S_API FAIL] SteamAPI_Init() failed; SteamAPI_IsSteamRunning() failed.
dlopen failed trying to load:
with error:
/home/server/.steam/sdk32/ cannot open shared object file: No such file or directory
Logging into anonymous gameserver account.
Fetching Workshop Addons..
Calling GetCollectionDetails
terminate called after throwing an instance of 'std::logic_error'
  what():  basic_string::_S_construct null not valid
./srcds_run: line 372:   474 Aborted                 (core dumped) $HL_CMD
cat: No such file or directory
email debug.log to
Wed Dec 18 09:00:48 UTC 2013: Server restart in 10 seconds

I’ve tried several collections, with various numbers of addons and maps with no success.
I’ve just rebooted the server for the kicks and still nothing.
Any ideas what is my problem?

Try launching this and post the results. Make sure to put your authkey back in.

./srcds_run -debug -game garrysmod +maxplayers 32 -authkey
[Censored] +gamemode sandbox +map ph_Prop_ink