ValueError: too many values to unpack (expected 2)

Am i doing something wrong?

$ makesurface vectorize gfs.t00z.pgrb2.0p25.f000 p.shp -g
Traceback (most recent call last):
File "/usr/local/bin/makesurface", line 9, in
load_entry_point('makesurface==0.0.8dev', 'console_scripts', 'makesurface')()
File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 610, in call
return self.main(_args, *_kwargs)
File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 590, in main
rv = self.invoke(ctx)
File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 936, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 782, in invoke
return ctx.invoke(self.callback, *_ctx.params)
File "/usr/local/lib/python2.7/dist-packages/click/core.py", line 416, in invoke
return callback(_args, **kwargs)
File "/disk/src/make-surface/makesurface/scripts/cli.py", line 57, in vectorize
makesurface.vectorize(infile, outfile, classes, classfile, weight, nodata, smoothing, band, carto, globewrap, axonometrize, nosimple, setnodata, nibble, rapfix)
File "/disk/src/make-surface/makesurface/init.py", line 4, in vectorize
vectorize_raster.vectorizeRaster(infile, outfile, classes, classfile, weight, nodata, smoothing, band, cartoCSS, globeWrap, axonometrize, nosimple, setNoData, nibbleMask, rapFix)
File "/disk/src/make-surface/makesurface/scripts/vectorize_raster.py", line 84, in vectorizeRaster
band = filter(lambda i: src.tags(i)['GRIB_ELEMENT'] == band, src.indexes)
File "/disk/src/make-surface/makesurface/scripts/vectorize_raster.py", line 84, in
band = filter(lambda i: src.tags(i)['GRIB_ELEMENT'] == band, src.indexes)
File "rasterio/_base.pyx", line 501, in rasterio._base.DatasetReader.tags (rasterio/_base.c:8978)
ValueError: too many values to unpack (expected 2)

Start by reproducing the command shown in the issue, then inspect makesurface/scripts/vectorize_raster.py at line 84 and the rasterio DatasetReader.tags call in the traceback. Done means the vectorize command no longer raises this ValueError for the reported input and produces the expected output.