[GHC] #8248: GHCi should not fail to honour ghci.conf or .ghci if group writable

[GHC]

#8248: GHCi should not fail to honour ghci.conf or .ghci if group writable
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        Reporter:  afcowie           |                Owner:  whisky
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:  7.10.2
       Component:  GHCi              |              Version:  7.6.3
      Resolution:  wontfix           |             Keywords:
Operating System:  Linux             |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #9324             |  Differential Rev(s):  Phab:D805
       Wiki Page:                    |
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Comment (by anohigisavay):

 I just got hit by this issue.

 I have been using ACL for more granular permission control. I created two
 users to access different desktop environments to avoid certain conflict
 issues, while essentially they are the same user and should be able to
 access each other's home directory without any problem. When ACL is
 enabled the group permission bits in the traditional UGO mechanism act as
 the mask for ACL (i.e. the maximum available permission for ACL_USER,
 ACL_GROUP_OBJ and ACL_GROUP). Thus it must be set to `rw-` instead of
 `r--`.

 This limitation renders ACL ineffective for the home directory.

 While it is obviously overkilling for GHCi to consider all these security
 enhancement mechanisms (SELinux and others also exist), I suggest we can
 leave the choice between security and flexibility to the users.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8248#comment:15>
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