only look for ALSA on linux systems

src/PortAudio.jl

@@ -315,6 +315,7 @@ function suppress_err(dofunc::Function)
 end
 
 function __init__()
+    if Sys.islinux()
         envkey = "ALSA_CONFIG_DIR"
         if envkey ∉ keys(ENV)
             searchdirs = ["/usr/share/alsa",
@@ -341,6 +342,7 @@ function __init__()
             confdir = searchdirs[confdir_idx]
             ENV[envkey] = confdir
         end
+    end
     # initialize PortAudio on module load. libportaudio prints a bunch of
     # junk to STDOUT on initialization, so we swallow it.
     # TODO: actually check the junk to make sure there's nothing in there we