Svn update could cause a build failure in existing trees

I’ve just merged a bunch of changes into the trunk
(I’ll talk about them in the next message.)

This update includes a rename of a swig .i file, and since our
computation of swig dependencies isn’t perfect, your build may fail
complaining that it can’t find gri_agc.i

This does not occur if you check out into an empty directory.

Here’s the work around:

Either before or after you update:

$ cd …/gnuradio-core/src/lib/swig
$ cp /dev/null gnuradio_swig_python.d
$ make clean

Then go back to the top and build as usual:

$ ./bootstrap …