Bug report from Satnam Singh, who tried to get an up to date GHC 
repository using darcs 2.3.1, freshly built today using GHC 6.10.4:

$ rm -rf ghc ; tar xf ghc-HEAD-2009-01-09-ghc-corelibs-testsuite.tar ; 
cd ghc ;
./darcs-all pull -a
== running darcs pull -a --repodir .
Pulling from "http://darcs.haskell.org/ghc"...
This is the GHC darcs repository (HEAD branch)

For more information, visit the GHC developer wiki at
   http://hackage.haskell.org/trac/ghc
**********************

darcs failed:  DeleteFile: permission denied (The process cannot access 
the file
  because it is being used by another process.)
Your repository is now in an inconsistent state.
This must be fixed by running darcs repair.

darcs failed: 512 at ./darcs-all line 69.

satnams@MSRC-LAGAVULIN /c/ghc/ghc
$ darcs -v
2.3.1 (release)

satnams@MSRC-LAGAVULIN /c/ghc/ghc
$ which ghc
/c/ghc/ghc-6.10.4/bin/ghc.exe

Hi Salvatore (and Petr),

Can you reproduce this?

Unfortunately I can't find ghc-HEAD-2009-01-09-ghc-corelibs-testsuite.tar on 
darcs.haskell.org. Where can I find it?

I am going to retry with ghc-HEAD-2009-09-09-ghc-corelibs-testsuite.tar.gz

Satnam

Ian says to try:
deleteable-2009-04-26/ghc-HEAD-2009-01-09-ghc-corelibs-testsuite.tar.bz2

It works for me :(.
Can you try outside of cygwin, with standard cmd.exe? Maybe with --no-cache 
option, to avoid a corrupted cache kicking in?

----8<---------
C:\Users\sinsalaco\Desktop\ghc-HEAD-2009-01-09-ghc-corelibs-
estsuite.tar\ghc>darcs pull -a --no-cache
Pulling from "http://darcs.haskell.org/ghc"...
This is the GHC darcs repository (HEAD branch)

For more information, visit the GHC developer wiki at
  http://hackage.haskell.org/trac/ghc
**********************
Reading inventory of repository C:/Users/sinsalaco/Desktop/ghc-HEAD-2009-01-09-

Finished pulling and applying.
----------8<---------

On Windows Vista I used darcs 2.3.1 (which I installed with “cabal update; cabal install darcs –f-curl”) and I used the ghc-HEAD-2009-09-09-ghc-corelibs-testsuite.tar.gz snapshot and now GHC builds. Thanks.

Satnam