[GHC] #16120: Hadrian should use cabal build-tools installed Alex and Happy if necessary

[GHC]

#16120: Hadrian should use cabal build-tools installed Alex and Happy if necessary
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        Reporter:  adamse            |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Build System      |              Version:  8.6.3
  (Hadrian)                          |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by snowleopard):

 > Yet another possibility might be to do new-exec instead of new-run to
 run hadrian after it is built by cabal. As hvr's example commands show
 alex and happy are available in PATH then.

 I actually thougth that `new-run` is the same as `new-exec` in this
 respect, so I expected that both Alex and Happy will be visible to
 Hadrian's `loopkupInPath`. Same for running Hadrian with Stack.

 Could you check if it works when using the current `build.cabal.sh`?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16120#comment:4>
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