xfce4-namebar-plugin$ ./waf build
Waf: Entering directory `/home/trent/Projects/xfce4-namebar-plugin/build'
Traceback (most recent call last):
  File "/home/trent/Projects/xfce4-namebar-plugin/.waf3-1.6.0-4af58e0fb0887da2c8138dcd73286cf0/waflib/Scripting.py", line 77, in waf_entry_point
    run_commands()
  File "/home/trent/Projects/xfce4-namebar-plugin/.waf3-1.6.0-4af58e0fb0887da2c8138dcd73286cf0/waflib/Scripting.py", line 129, in run_commands
    run_command(cmd_name)
  File "/home/trent/Projects/xfce4-namebar-plugin/.waf3-1.6.0-4af58e0fb0887da2c8138dcd73286cf0/waflib/Scripting.py", line 122, in run_command
    ctx.execute()
  File "/home/trent/Projects/xfce4-namebar-plugin/.waf3-1.6.0-4af58e0fb0887da2c8138dcd73286cf0/waflib/Scripting.py", line 308, in execute
    return execute_method(self)
  File "/home/trent/Projects/xfce4-namebar-plugin/.waf3-1.6.0-4af58e0fb0887da2c8138dcd73286cf0/waflib/Build.py", line 99, in execute
    self.execute_build()
  File "/home/trent/Projects/xfce4-namebar-plugin/.waf3-1.6.0-4af58e0fb0887da2c8138dcd73286cf0/waflib/Build.py", line 102, in execute_build
    self.recurse([self.run_dir])
  File "/home/trent/Projects/xfce4-namebar-plugin/.waf3-1.6.0-4af58e0fb0887da2c8138dcd73286cf0/waflib/Context.py", line 117, in recurse
    user_function(self)
  File "/home/trent/Projects/xfce4-namebar-plugin/wscript", line 65, in build
    defines      = ['WNCK_I_KNOW_THIS_IS_UNSTABLE'])
  File "/home/trent/Projects/xfce4-namebar-plugin/.waf3-1.6.0-4af58e0fb0887da2c8138dcd73286cf0/waflib/Configure.py", line 228, in fun
    return f(*k,**kw)
  File "/home/trent/Projects/xfce4-namebar-plugin/.waf3-1.6.0-4af58e0fb0887da2c8138dcd73286cf0/waflib/Tools/c_aliases.py", line 52, in program
    set_features(kw,'program')
  File "/home/trent/Projects/xfce4-namebar-plugin/.waf3-1.6.0-4af58e0fb0887da2c8138dcd73286cf0/waflib/Tools/c_aliases.py", line 50, in set_features
    kw['features']=Utils.to_list(kw.get('features',[]))+Utils.to_list(sniff_features(**kw))
  File "/home/trent/Projects/xfce4-namebar-plugin/.waf3-1.6.0-4af58e0fb0887da2c8138dcd73286cf0/waflib/Tools/c_aliases.py", line 19, in sniff_features
    exts=get_extensions(kw['source'])
KeyError: 'source'