hackrf tools fail with hackrf kernel module

[Robin Sheat]

When I plug in a hackrf, it loads the hackrf kernel module.

This takes over connection to the device, meaning that hackrf_info doesn't work:

$ hackrf_info
hackrf_open() failed: HACKRF_ERROR_LIBUSB (-1000)

other things relying on the hackrf don't work either, like gqrx.

Removing the module makes things happy again:

$ sudo rmmod hackrf
$ hackrf_info
Found HackRF board.
Board ID Number: 2 (HackRF One)
Firmware Version: 2014.08.1
Part ID Number: ...
Serial Number: ...

The obvious workaround is to blacklist the module, but I bet this behaviour will confuse a lot of people new to this while they cast around trying to figure out why it's broken.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: hackrf 2014.08.1-1
ProcVersionSignature: Ubuntu 3.19.0-18.18-generic 3.19.6
Uname: Linux 3.19.0-18-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.1
Architecture: amd64
CurrentDesktop: Unity
Date: Sat May 23 12:28:50 2015
EcryptfsInUse: Yes
InstallationDate: Installed on 2013-01-21 (851 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5)
SourcePackage: hackrf
UpgradeStatus: Upgraded to vivid on 2015-05-22 (0 days ago)