Built from master, tried running the bid-ask datafeed example, and got the following results:
1: 2010-02-03T23:59:59.999989 - Bid 0.5346 - 0.5347 Ask
2: 2010-02-03T23:59:59.999989 - Bid 0.5343 - 0.5347 Ask
3: 2010-02-03T23:59:59.999989 - Bid 0.5543 - 0.5545 Ask
4: 2010-02-03T23:59:59.999989 - Bid 0.5342 - 0.5344 Ask
5: 2010-02-03T23:59:59.999989 - Bid 0.5245 - 0.5464 Ask
6: 2010-02-03T23:59:59.999989 - Bid 0.5460 - 0.5470 Ask
7: 2010-02-03T23:59:59.999989 - Bid 0.5824 - 0.5826 Ask
8: 2010-02-03T23:59:59.999989 - Bid 0.5371 - 0.5374 Ask
9: 2010-02-03T23:59:59.999989 - Bid 0.5793 - 0.5794 Ask
10: 2010-02-03T23:59:59.999989 - Bid 0.5684 - 0.5688 Ask
In the source data file, every line has a different timestamp. I ran into the same issue with my own bid-ask data, looks like an issue with the timestamp() function in linebuffer.py.