+ case exit_code of
+ ExitSuccess ->
+ return ()
+ -- rawSystem returns (ExitFailure 127) if the exec failed for any
+ -- reason (eg. the program doesn't exist). This is the only clue
+ -- we have, but we need to report something to the user because in
+ -- the case of a missing program there will otherwise be no output
+ -- at all.
+ ExitFailure 127 ->
+ throwDyn (InstallationError ("could not execute: " ++ pgm))
+ ExitFailure _other ->
+ throwDyn (PhaseFailed phase_name exit_code)