odd error trying to hack FastString implementation

[Isaac Dupree]

Stefan O'Rear wrote:
> You patched GHC, so the version number (which is extracted from darcs)
> automatically went up.  GHC assumes (incorrectly) that this broke the
> interface format, and is trying to stop you from shooting yourself in
> the foot.

But this was from a clean checkout that only contained HEAD plus those 
patches, using ./validate (so j=2), and the second time after make 
distclean (which I wouldn't necessarily trust, but the first time I also 
got an error in the same place).

Here is a small sampling from the first time:

make[2]: Entering directory 
`/Users/me/modified/ghc-7_1/libraries/containers'
../../compiler/stage1/ghc-inplace -package-name containers-0.1 
-hide-all-packages -i -idist/build/autogen -idist/build -i. -Idist/build 
-odir dist/build -hidir dist/buil
d -package base-2.1 -package array-0.1 -O -fglasgow-exts -XCPP 
-idist/build  -H128m -O -fasm -O -fasm -fgenerics -c Data/Sequence.hs -o 
dist/build/Data/Sequence.o  -ohi
dist/build/Data/Sequence.hi
../../compiler/stage1/ghc-inplace -package-name containers-0.1 
-hide-all-packages -i -idist/build/autogen -idist/build -i. -Idist/build 
-odir dist/build -hidir dist/buil
d -package base-2.1 -package array-0.1 -O -fglasgow-exts -XCPP 
-idist/build  -H128m -O -fasm -O -fasm -fgenerics -c Data/IntSet.hs -o 
dist/build/Data/IntSet.o  -ohi dist
/build/Data/IntSet.hi

Data/Sequence.hs:108:0:
     Can't find interface-file declaration for variable 
Data.Foldable.$dmfold
       Probable cause: bug in .hi-boot file, or inconsistent .hi file
       Use -ddump-if-trace to get an idea of which file caused the error
     In the expression: Data.Foldable.$dmfold
     In the definition of `fold': fold = Data.Foldable.$dmfold
     In the definition for method `fold'

Data/Sequence.hs:108:0:
     Can't find interface-file declaration for variable 
Data.Foldable.$dmfoldMap
       Probable cause: bug in .hi-boot file, or inconsistent .hi file
       Use -ddump-if-trace to get an idea of which file caused the error
     In the expression: Data.Foldable.$dmfoldMap
     In the definition of `foldMap': foldMap = Data.Foldable.$dmfoldMap
     In the definition for method `foldMap'

Data/Sequence.hs:118:0:
     Can't find interface-file declaration for variable 
Data.Traversable.$dmsequenceA
       Probable cause: bug in .hi-boot file, or inconsistent .hi file
       Use -ddump-if-trace to get an idea of which file caused the error
     In the expression: Data.Traversable.$dmsequenceA
     In the definition of `sequenceA':
.................

And the second time:
make[2]: Entering directory 
`/Users/me/modified/ghc-7_1/libraries/containers'
../../compiler/stage1/ghc-inplace -package-name containers-0.1 
-hide-all-packages -i -idist/build/autogen -idist/build -i. -Idist/build 
-odir dist/build -hidir dist/buil
d -package base-2.1 -package array-0.1 -O -fglasgow-exts -XCPP 
-idist/build  -H128m -O -fasm -O -fasm -fgenerics -c Data/Sequence.hs -o 
dist/build/Data/Sequence.o  -ohi
dist/build/Data/Sequence.hi
/Users/me/modified/ghc-7_1/libraries/base/dist/build/GHC/Read.hi
Declaration for Read
Class op GHC.Read.readsPrec
          GHC.Base.Int -> Text.ParserCombinators.ReadP.ReadS a:
   Bad interface file: 
/Users/me/modified/ghc-7_1/libraries/base/dist/build/Text/ParserCombinators/ReadP.hi
       Something is amiss; requested module 
base:Text.ParserCombinators.ReadP differs from name found in the 
interface file base:Text.ParserCombinators.ReadP
Cannot continue after interface file error
make[2]: *** [dist/build/Data/Sequence.o] Error 1
make[2]: Leaving directory `/Users/me/modified/ghc-7_1/libraries/containers'
make[1]: *** [make.library.containers] Error 2
make[1]: Leaving directory `/Users/me/modified/ghc-7_1/libraries'
make: *** [stage1] Error 2



Isaac