[GHC] #8276: Building Haddock documentation panics with perf build on x86_64 Linux

[GHC]

#8276: Building Haddock documentation panics with perf build on x86_64 Linux
---------------------------------------+----------------------------------
        Reporter:  jstolarek           |            Owner:  thoughtpolice
            Type:  bug                 |           Status:  new
        Priority:  highest             |        Milestone:  7.8.1
       Component:  Documentation       |          Version:  7.7
      Resolution:                      |         Keywords:
Operating System:  Unknown/Multiple    |     Architecture:  x86_64 (amd64)
 Type of failure:  Compile-time crash  |       Difficulty:  Unknown
       Test Case:                      |       Blocked By:
        Blocking:                      |  Related Tickets:
---------------------------------------+----------------------------------
Changes (by thoughtpolice):

 * owner:   => thoughtpolice
 * priority:  high => highest
 * milestone:   => 7.8.1


Comment:

 I'll be looking into this. After talking about it, me and SPJ are honestly
 just inclined to delete the whole save/restore static flag code, since it
 doesn't really seem like it works anyway (re: Simon M's point #1 above,
 regarding the CAFs that cannot be reset.) This doesn't change the reality
 of #2 though: with GHCi being dynamic, `v_opt_C_ready` will already be set
 in GHCi, since we only use one copy of the GHC package. But this would
 completely eliminate this problem, although DocTest needs to be updated
 then.

 I attempted to begin removing the remaining static flags, but it quickly
 got extremely painful - removing the last ones will require quite a bit of
 refactoring as changing them to `DynFlag` entries makes the changes
 extremely pervasive (leaking into the wired-ins API, for example.)

 Simon H, neither of us really understood what DocTest needs this for - to
 run `createInterfaces` several times apparently, but I'm not sure what the
 implications of that are. The remaining static flags only control very
 basic  things, meant mostly for debugging - why does DocTest require
 saving them, exactly? Do you have a better suggestion of what should
 happen? Because this must be fixed, and I'm inclined to just delete broken
 code, rather than paper around it with more odd behavior that's difficult
 to comprehend.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8276#comment:28>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler