(January 16, 2016) I encounted a segmentation fault in the function
rs_search_for_block of librsync while running the Duplicity backup tool. This crash appears to be related to this bug.
In the meantime, I used the following commands to switch back to old versions of librsync and duplicity:
brew switch librsync 0.9.7 brew switch duplicity 0.6.26_1