[Seqan-dev] Trouble using SequenceStream

[Theodore Omtzigt <theo@stillwater-sc.com>]

I am getting stuck on the simplest of tasks, reading an uncompressed
fastq file. This statement:
          seqan::SequenceStream seqIO(argv[1]);

returns a FILE_FORMAT_ERROR on a valid fastq text file. In
sequence_stream.h in the function _checkFormat, checkStreamFormat
returns false,

    // Guess file format, given the record reader.
    template <typename TStream, typename TSpec>
    SeqIOFileFormat_::Type _checkFormat(RecordReader<TStream, TSpec> &
recordReader)
    {
        AutoSeqStreamFormat formatTag;
        if (!checkStreamFormat(recordReader, formatTag))
            return SeqIOFileFormat_::FILE_FORMAT_ERROR;

The recursion in checkStreamFormat in guess_stream_format.h is confusing
me so I can't figure out what specific failure it is tripping over. I am
trying to debug this but need some help deciphering the recursion
architecture of the guessFormat code.

How do I know it is a valid fastq file? The file provided has been a
test file for non seqan code, and I have been able to use it in seqan
with the FragmentStore without trouble.