GOES Composites failling

[simonrp84]

Describe the bug
If I try to create a composite based upon a GOES-16 image then I get an error message saying that there is no matching dataset

To Reproduce

# Your code here
from		satpy			 import Scene
from		glob				 import glob
import	os

BASE_DIR		=	{my_in_dir}
OUT_DIR		=	{my_out_dir}

count			=	0
fnames	=	glob(os.path.join(BASE_DIR, 'OR*-Rad*-*C01*.nc'))
fnames.sort()

incount			=	1
f		=	fnames[0]

infs	=	glob(f.replace('C01', 'C*')[:len(BASE_DIR) + 50] + '*.nc')
scn	=	Scene(reader='abi_l1b', filenames=infs)

print('	-	Processing',incount,'of',len(fnames))
scn.load(['convection'])
new	=	scn.resample(scn.min_area(), resampler='native')
outf	=	OUT_DIR+'GOES_'+str(incount).zfill(4)+'.png'

new.save_dataset('convection', outf)

**Expected behavior**
A PNG file to be created in OUT_DIR that shows the generated convection composite for a given timeslot.

**Actual results**
Traceback (most recent call last):
  File "/network/aopp/apres/users/proud/Progs/conda/lib/python3.6/site-packages/satpy/readers/__init__.py", line 301, in __getitem__
    return super(DatasetDict, self).__getitem__(item)
KeyError: 'convection'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/network/aopp/apres/users/proud/Progs/conda/lib/python3.6/site-packages/satpy/scene.py", line 1043, in save_dataset
    return writer.save_dataset(self[dataset_id],
  File "/network/aopp/apres/users/proud/Progs/conda/lib/python3.6/site-packages/satpy/scene.py", line 616, in __getitem__
    return self.datasets[key]
  File "/network/aopp/apres/users/proud/Progs/conda/lib/python3.6/site-packages/satpy/readers/__init__.py", line 303, in __getitem__
    key = self.get_key(item)
  File "/network/aopp/apres/users/proud/Progs/conda/lib/python3.6/site-packages/satpy/readers/__init__.py", line 292, in get_key
    best=best, **dfilter)
  File "/network/aopp/apres/users/proud/Progs/conda/lib/python3.6/site-packages/satpy/readers/__init__.py", line 243, in get_key
    raise KeyError("No dataset matching '{}' found".format(str(key)))
KeyError: "No dataset matching 'DatasetID(name='convection', wavelength=None, resolution=None, polarization=None, calibration=None, level=None, modifiers=None)' found"



**Environment Info:**
Ubuntu 14.04 LTS + Ubuntu 18.04
Python 3.6, SatPy 0.10.0

**Additional context**
All 16 GOES NetCDF files are available in the BASE_DIR, missing channels is not the problem.

[djhoese]

Thanks @simonrp84. You found a legit bug and I've fixed it in #553. It should be released in satpy 0.11 next week hopefully.

[simonrp84]

Thanks all. I don't know how to make SatPy from github, so I'll wait for the next release :)

[mraspaud]

pip install git+https://github.com/pytroll/satpy.git :)

[simonrp84]

Cheers Martin, that works!