[GHC] #910: --make should have a -j flag for parallel building

[GHC]

#910: --make should have a -j flag for parallel building
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        Reporter:  igloo             |            Owner:
            Type:  feature request   |           Status:  patch
        Priority:  normal            |        Milestone:  _|_
       Component:  Compiler          |          Version:  6.4.2
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:  N/A               |       Blocked By:  8184
        Blocking:                    |  Related Tickets:
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Comment (by rrnewton):

 Have you tested `cabal -j` on this branch?  They *should* compose fine,
 and I'd love to see what kind of speedup one can get installing the
 Haskell Platform packages.

 Unfortunately, right now I get a whole bunch of undefined reference errors
 when I try something like this:

    time cabal-1.18.0 install -j30 --disable-library-profiling --disable-
 documentation HUnit --reinstall

 Btw, I see the same problem with cabal 1.16.0.2.  But taking away the -j30
 makes it work.  I do NOT have the same problem on master (8c99e698476291c)
 presently, nor on earlier versions of HEAD from 2013.08.04.  (Yet, this
 might have nothing to do with parcs patches, of course.  There are another
 ~46 patches that are on master but not on the `ghc-parmakegsoc` branch.
 Fast forwarding the branch will be my next step.)

 Notice that, weirdly, this problem occurs even when `ghc -j` is not used
 (as above).

 For reference here is a sample of the errors:

 {{{
 cabal-1.17.0-HEAD-20130802: Error: some packages failed to install:
 HUnit-1.2.5.2 failed during the configure step. The exception was:
 user error
 (/home/beehive/ryan_scratch/ghc-parGSOC2/libraries/Cabal/Cabal/dist-
 install/build/libHSCabal-1.18.0.a(Simple__64.o):
 In function `chbT_info':
 (.text+0x857): undefined reference to `rff5_info'
 /home/beehive/ryan_scratch/ghc-parGSOC2/libraries/Cabal/Cabal/dist-
 install/build/libHSCabal-1.18.0.a(Simple__64.o):
 In function `sg4L_info':
 ...
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/910#comment:41>
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