[Discuss-gnuradio] module install Error: Unable to find 'pmt_swig.i'

[md123]

using the usual method, i am trying to install the 4fsk demodulator block and i 
get this error:

make[2]: Entering directory `/home/matt/gr-fsk4/src/lib'
/usr/bin/swig -c++ -fvirtual -python -modern -I/usr/local/include/gnuradio/swig 
-I/usr/local/include/gnuradio -module fsk4 -o fsk4.cc ../../src/lib/fsk4.i
/usr/local/include/gnuradio/swig/gr_basic_block.i:26: Error: Unable to find 
'pmt_swig.i'

the pmt_swig.i file is one of the directories here (usr/ 
local/include/gruel/swig) and note that when i execute op25 (another decoder 
block which uses the fsk4) the first output line is "Imported legacy fsk4". so 
now i am confused as to how grc is importing the fsk4 if i cant even install it?


Thanks guys,
Matt