[GHC] #14017: "make install" with non-standard umask causes bad permission on package.cache

[GHC]

#14017: "make install" with non-standard umask causes bad permission on
package.cache
-------------------------------------+-------------------------------------
        Reporter:  djf               |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.2.2
       Component:  Build System      |              Version:  8.2.1
      Resolution:                    |             Keywords:
Operating System:  Linux             |         Architecture:
 Type of failure:  Installing GHC    |  Unknown/Multiple
  failed                             |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #13375, #13354,   |  Differential Rev(s):
  #13194                             |
       Wiki Page:                    |
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Changes (by bgamari):

 * cc: arybczak (added)
 * related:   => #13375, #13354, #13194


Comment:

 I believe this more fallout from the atomic package database modification
 patch. The problem appears to be that `writeFileAtomic` (which is used by
 `writePackageDb` to populate the package database cache) uses the create-
 and-rename trick for atomic writes on POSIX platforms. However, when it
 creates the new file it doesn't take care to set the mode bits. It's not
 clear to me what should be done about this; what is the "correct" mode for
 this file?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14017#comment:2>
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