I am having a DVB-S card

00:08.0 Multimedia controller [0480]: Philips Semiconductors SAA7146
[1131:7146]

and when I run

dvbscan /usr/share/dvb/dvb-s/Astra-19.2E

it reports "Failed to set frontend".  However, downloading
http://www.linuxtv.org/download/dvb/linuxtv-dvb-apps-1.1.1.tar.bz2 and
building myself leads to a util/scan/scan that does work.

I'm trying to scan a Hauppauge Nova-T Stick and it gives the same error:

# dvbscan /usr/share/dvb/dvb-t/es-Madrid
Unable to query frontend status

frontend exists though:
# ls -l /dev/dvb/adapter0/
total 0
crw-rw---- 1 root video 212, 4 2009-04-08 13:58 demux0
crw-rw---- 1 root video 212, 5 2009-04-08 13:58 dvr0
crw-rw---- 1 root video 212, 3 2009-04-08 13:58 frontend0
crw-rw---- 1 root video 212, 7 2009-04-08 13:58 net0

and log says:

[ 1061.788178] dvb-usb: found a 'Hauppauge Nova-T Stick' in warm state.
[ 1061.788306] dvb-usb: will pass the complete MPEG2 transport stream to
the software
demuxer.
[ 1061.791182] DVB: registering new adapter (Hauppauge Nova-T Stick)
[ 1062.008970] DVB: registering frontend 0 (DiBcom 7000PC)...
[ 1062.196566] DiB0070: successfully identified

Hello Sebastian, hello Eric,
I stumbled over the same error and found this report, so I attach
my findings to it - even when this report is alreay quite old ...

As of today it seems "dvbscan" has more than one problem:
- needed input file format seems more like
    /usr/share/dvb/dvb-legacy/dvb-s/Astra-19.2E
- polarization from the input file gets not used
    (Failed to set frontend)
- return value of dvbfe_get_info is checked wrong
    (Unable to query frontend status)
- when we succeed above we get into function dvbscan_scan_dvb
    which is empty ???

Therefore, in my opinion, the file /usr/bin/dvbscan in its current
state is useless.

When you was building from source you already used instead
of util/dvbscan/dvbscan the executable util/scan/scan.

That one from the package worked flawless for me (at least DVB-S):

$ /usr/bin/scan /usr/share/dvb/dvb-legacy/dvb-s/Astra-19.2E
scanning /usr/share/dvb/dvb-legacy/dvb-s/Astra-19.2E
using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
initial transponder 12551500 V 22000000 5
DVB-S IF freq is 1951500
...
0x0011 0x0fa7: pmt_pid 0x0000 (null) -- Thomson SAT IPDL (running)
Network Name 'BetaDigital'
dumping lists (1223 services)
...


Kind regards,
Bernhard