--show-iface panics with HEAD

Let's say I compile an empty module:

module Foo where

Now, this works:

ghc-stage2 --show-iface Foo.hi

But this panics:

ghc-stage2 Foo.hi --show-iface

ghc-stage2: panic! (the 'impossible' happened)
  (GHC version 7.9.20141120 for x86_64-unknown-linux):
        ghc-stage2: panic! (the 'impossible' happened)
  (GHC version 7.9.20141120 for x86_64-unknown-linux):
        v_unsafeGlobalDynFlags: not initialised

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

Does not happen with 7.8.3. I guess one of recent DynFlags changes must have caused this.

Trac metadata

Trac field	Value
Version	7.9
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Driver
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