[GHC] #11544: SCC call-stack from `error` missing call-sites

[GHC]

#11544: SCC call-stack from `error` missing call-sites
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           Reporter:  gridaphobe     |             Owner:
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Profiling      |           Version:  8.0.1-rc1
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 For some reason the `-prof` stack that `error` attaches only includes the
 top-level CAF. This is with the default build settings (which I believe
 are the release settings?)

 {{{
 $ cat Foo.hs
 main = print (foo [1])
 foo xs = tail (tail xs)

 $ ./inplace/bin/ghc-stage2 --make -prof -fprof-auto-calls Foo.hs
 [1 of 1] Compiling Main             ( Foo.hs, Foo.o ) [flags changed]
 Linking Foo ...

 $ ./Foo
 Foo: Prelude.tail: empty list
 CallStack (from -prof):
   GHC.List.CAF (<entire-module>)
 }}}

 I would expect to at least see the call-site of `foo` (if not also `tail`)
 in the stack.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11544>
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