GLTracesim Build issue

[maitpate]

HI,
I am trying to build GLtracesim generator by this cmd :
scons mode=debug++ -j4 proto

Getting below 3 errors :
scons: Reading SConscript files ...
TypeError: startswith first arg must be bytes or a tuple of bytes, not str:
File "/home/maitpate/gltracesim/gltracesim/SConstruct", line 110:
configure_png(simulator)
File "/home/maitpate/gltracesim/gltracesim/SConstruct", line 108:
env.Append(LIBS = libpng("ldflags"))
File "/home/maitpate/gltracesim/gltracesim/SConstruct", line 101:
if r.startswith("-l"):

I have followed all the steps as mentioned in the READme. Am I missing something here ?
Thanks.