make distclean

[Manuel M T Chakravarty]

...doesn't clean the dist directories.

After ./darcs-all pull today, validate dies with errors, such as

../../compiler/stage1/ghc-inplace -package-name Cabal-1.1.7 
-hide-all-packages -i -idist/build/autogen -idist/build -i. 
-Idist/build -optc-DCABAL_VERSION=1,1,7 -odir dist/build 
-hidir dist/build -package base-2.1 -package filepath-1.0 
-package pretty-1.0 -package directory-1.0 -package 
old-time-1.0 -package process-1.0 -O -DCABAL_VERSION=1,1,7 
-Wall -cpp -idist/build  -H64m -Onot -fasm -O -fasm -c 
Distribution/Configuration.hs -o 
dist/build/Distribution/Configuration.o  -ohi 
dist/build/Distribution/Configuration.hi

Distribution/Version.hs:72:0:
     Bad interface file: dist/build/Distribution/Compat/ReadP.hi
         mismatched interface file versions: expected 
60720070729, found 60720070726
make[2]: *** [dist/build/Distribution/Version.o] Error 1
make[2]: *** Waiting for unfinished jobs....

I got a similar one in base/.

It seems as if the "make distclean" at the start of validate 
doesn't clean out the "dist/" directories in libraries/.

Manuel