I bumped into a segmentation fault in the regex library today and thought I'd warn others in case similar behavior is observed:
Prelude> :m Text.Regex
Prelude Text.Regex> map read (splitRegex (mkRegex "\\|") "0|1|2|4") :: [Int]
Loading package syb ... linking ... done.
Loading package array-0.2.0.0 ... linking ... done.
Loading package bytestring-0.9.1.4 ... linking ... done.
Loading package regex-base-0.72.0.2 ... linking ... done.
Loading package regex-posix-0.72.0.3 ... linking ... done.
Loading package regex-compat-0.71.0.1 ... linking ... done.
[0,1,2,4]
Prelude Text.Regex> Segmentation fault