[GHC] #3878: doesFileExist doesn't work for some /dev files in ghc 6.12

[GHC]

#3878: doesFileExist doesn't work for some /dev files in ghc 6.12
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    Reporter:  marcotmarcot    |       Owner:                             
        Type:  bug             |      Status:  new                        
    Priority:  normal          |   Component:  Compiler                   
     Version:  6.12.1          |    Keywords:                             
          Os:  Linux           |    Testcase:                             
Architecture:  x86_64 (amd64)  |     Failure:  Incorrect result at runtime
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 Hi.  I've noticed this with a program that checks for a lvm image.  Here's
 the situation:

 Prelude System.Directory> doesFileExist "/dev/null"
 True
 Prelude System.Directory> doesFileExist "/dev/stdin"
 True
 Prelude System.Directory> doesFileExist "/dev/sda0"
 False
 Prelude System.Directory> doesFileExist "/dev/zezinho/sid"
 False

 All of these files exist in my system:

 marcot at zezinho:/dev$ ls -l null sda1 stdin zezinho/sid /proc/self/fd/0
 mapper/zezinho-sid /dev/pts/5
 crw--w---- 1 marcot tty    136, 5 Fev 12 09:09 /dev/pts/5
 brw-rw---- 1 root   disk   254, 4 Fev 12 08:55 mapper/zezinho-sid
 crw-rw-rw- 1 root   root     1, 3 Fev 12 08:33 null
 lrwx------ 1 marcot marcot     64 Fev 12 09:09 /proc/self/fd/0 ->
 /dev/pts/5
 brw-rw---- 1 root   disk     8, 1 Fev 12 08:55 sda1
 lrwxrwxrwx 1 root   root       15 Fev 12 08:33 stdin -> /proc/self/fd/0
 lrwxrwxrwx 1 root   root       21 Fev 12 08:55 zezinho/sid -> ../mapper
 /zezinho-sid

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Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3878>
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