When trying to flash a Galaxy S3 (ATT), I get
ERROR: Failed to detect compatible download-mode device.
below is the log,
$ sudo heimdall flash --RECOVERY recovery.img Heimdall v1.4.0 Copyright (c) 2010-2013, Benjamin Dobell, Glass Echidna http://www.glassechidna.com.au/ This software is provided free of charge. Copying and redistribution is encouraged. If you appreciate this software and you would like to support future development please consider donating: http://www.glassechidna.com.au/donate/ Initialising connection... Detecting device... ERROR: Failed to detect compatible download-mode device.