[GHC] #8144: Interface hashes include time stamp of dependent files (UsageFile mtime)

[GHC]

#8144: Interface hashes include time stamp of dependent files (UsageFile mtime)
-------------------------------------+-------------------------------------
        Reporter:  nh2               |                   Owner:
            Type:  bug               |                  Status:  infoneeded
        Priority:  normal            |               Milestone:  7.12.1
       Component:  Compiler          |                 Version:  7.6.3
      Resolution:                    |                Keywords:  testcase
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  performance bug                    |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
-------------------------------------+-------------------------------------
Changes (by nomeata):

 * priority:  high => normal


Comment:

 Ah, wait: This is only waiting for a test case, right?

 So then why do I still see this
 {{{
 ./usr/lib/ghc/base-4.7.0.2/System/Info.hi
 --- /dev/fd/63  2015-05-14 10:15:20.278404032 +0200
 +++ /dev/fd/62  2015-05-14 10:15:20.278404032 +0200
 @@ -5,7 +5,7 @@
  Way: Wanted [],
       got    []
  interface base:System.Info 7084
 -  interface hash: 038b3a2a32cd43c6a82b096e3ef5c665
 +  interface hash: 4ff1db7940716ca0e906d3f6b7af1166
    ABI hash: 67cae6f933216805d975ee28cd5ea72d
    export-list hash: 89e8b7a3bfc33bdb505eb586ca9fe64e
    orphan hash: 693e9af84d3dfcc71e640e005bdc5e2e
 @@ -64,7 +64,7 @@
    divMod e11d60a38cd49de2f6058cc39227517a
  import safe Prelude 74043f272d60acec1777d3461cfe5ef4
    exports: be888345b248b32ace8f805dd49f3def
 -addDependentFile "/build/ghc-LIQtDg/ghc-7.8.4/includes/ghcplatform.h"
 +addDependentFile "/build/ghc-Na5lKv/ghc-7.8.4/includes/ghcplatform.h"
  addDependentFile "libraries/base/dist-
 install/build/autogen/cabal_macros.h"
  addDependentFile "/usr/include/stdc-predef.h"
  f85496685a82c42827c38c1ecec0b5fd
 }}}
 Looks like the filename is included in the hash then, because the files
 are identical in both builds...

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8144#comment:33>
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