Move OS version check into main body and have it throw an exception on failure so the import fails.

terminatorlib/freebsd.py

@@ -39,20 +39,19 @@ class kinfo_file(Structure):
       ('kf_sa_peer',       sockaddr_storage),
   ]
 
-
-def get_process_cwd(pid):
 libc = CDLL('libc.so')
 
 len = c_uint(sizeof(c_uint))
 ver = c_uint(0)
 
 if (libc.sysctlbyname('kern.osreldate', byref(ver), byref(len), None, 0) < 0):
-    return None
+  raise OSError, "sysctlbyname returned < 0"
 
 # kern.proc.filedesc added for procstat(1) after these __FreeBSD_versions
 if ver.value < 700104 and ver.value < 800019:
-    return None
+  raise NotImplementedError, "cwd detection requires a recent 7.0-STABLE or 8-CURRENT"
 
+def get_process_cwd(pid):
   # /usr/include/sys/sysctl.h
   # CTL_KERN, KERN_PROC, KERN_PROC_FILEDESC
   oid = (c_uint * 4)(1, 14, 14, pid)