Bug#835971: debsnap silently ignores download errors

[Jakub Wilk]

Package: devscripts
Version: 2.16.7
Usertags: serious

If debsnap fails to download a file (see #835967), there's no error 
message and exit code is 0:

$ debsnap --verbose -a i386 nvidia-kernel-source 340.65-1
Getting json http://snapshot.debian.org/mr/binary/nvidia-kernel-source/
Getting json http://snapshot.debian.org/mr/package/nvidia-graphics-drivers/340.65-1/binfiles/nvidia-kernel-source/340.65-1?fileinfo=1
Getting file nvidia-kernel-source_340.65-1_i386.deb: http://snapshot.debian.org/file/e3a6c2f3e2bdd9e073efc86f06f2c74d52d4aeea

$ echo $?
0

$ dpkg -c */*.deb > /dev/null
dpkg-deb (subprocess): cannot copy archive member from 'binary-nvidia-kernel-source/nvidia-kernel-source_340.65-1_i386.deb' to decompressor pipe: unexpected end of file or stream
dpkg-deb (subprocess): decompressing archive member: lzma error: unexpected end of input
tar: Unexpected EOF in archive
tar: Error is not recoverable: exiting now
dpkg-deb: error: subprocess tar returned error exit status 2

-- 
Jakub Wilk