id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,os,architecture,failure,difficulty,testcase,blockedby,blocking,related
5783,Data.Text.isPrefixOf fails to terminate,reinerp,,"The function {{{Data.Text.isPrefixOf}}} fails to terminate with GHC 7.4-rc1, although it terminates with GHC-7.2. Reproduction instructions:

{{{
$ cd ghc-7.4.0.20111219
$ sudo make install
$ cabal -V
cabal-install version 0.10.2
using version 1.10.1.0 of the Cabal library 
$ cabal install text-0.11.1.12
$ cd /tmp
$ cat >Test.hs
import Data.Text
main = print (pack ""A"" `isPrefixOf` pack ""AB"")
$ runghc Test.hs
<program hangs on 100% CPU use, without producing any output>
}}}

Unfortunately, it appears to be rather difficult to create a reduced test case; the problem disappears when I make any attempt to minimize it.

I have verified this on Mac OS X 10.7.2 and 64-bit Ubuntu 10.10.",bug,closed,highest,7.4.1,Compiler,7.4.1-rc1,invalid,,leon.p.smith@…,MacOS X,x86_64 (amd64),Incorrect result at runtime,Unknown,,,,