Two things I don't understand:-
1) Why does apt-get source fetch a different source package to the one named
in the arg?
2) Why can't key 0x92D284CF33C66596 be found?
$ apt-get source linux-image-3.13.0-76-generic
Reading package lists... Done
Building dependency tree
Reading state information... Done
Picking 'linux' as source package instead of 'linux-image-3.13.0-76-generic'
...
Need to get 124 MB of source archives.
Get:1 http://es.archive.trisquel.info/trisquel/ belenos-updates/main linux
3.13.0-77.121+7.0trisquel2 (dsc) [7,481 B]
Get:2 http://es.archive.trisquel.info/trisquel/ belenos-updates/main linux
3.13.0-77.121+7.0trisquel2 (tar) [124 MB]
Fetched 124 MB in 2min 3s (1,008 kB/s)
gpgv: Signature made Tue 02 Feb 2016 00:43:48 GMT using RSA key ID 33C66596
gpgv: Can't check signature: public key not found
dpkg-source: warning: failed to verify signature on
./linux_3.13.0-77.121+7.0trisquel2.dsc
dpkg-source: info: extracting linux in linux-3.13.0
dpkg-source: info: unpacking linux_3.13.0-77.121+7.0trisquel2.tar.gz
$ gpg2 --verify linux_3.13.0-77.121+7.0trisquel2.dsc
gpg: Signature made Tue 02 Feb 2016 00:43:48 GMT
gpg:using RSA key 0x92D284CF33C66596
gpg: Can't check signature: No public key
$ torsocks gpg2 --keyserver jirk5u4osbsr34t5.onion --recv-keys
0x92D284CF33C66596
gpg: requesting key 0x92D284CF33C66596 from hkp server jirk5u4osbsr34t5.onion
gpgkeys: key 92D284CF33C66596 not found on keyserver
gpg: no valid OpenPGP data found.
gpg: Total number processed: 0