Can't install packages with my inplace compiler

[Simon Peyton Jones]

It says 

simonpj at cam-05-unx:~/tmp/singletons-1.0$ cabal --version
cabal-install version 1.21.0.0
using version 1.21.0.0 of the Cabal library


Oddly if I try "cabal update; cabal install cabal-install" it says:
	Resolving dependencies...
	Downloading Cabal-1.20.0.2...

so it looks as if it's about to install an *older* version than the one I have already!

What now?

Thanks

SImon

|  -----Original Message-----
|  From: Herbert Valerio Riedel [mailto:hvriedel at gmail.com]
|  Sent: 04 November 2014 11:20
|  To: Simon Peyton Jones
|  Cc: GHC Devs
|  Subject: Re: Can't install packages with my inplace compiler
|  
|  Hello Simon,
|  
|  On 2014-11-04 at 11:55:48 +0100, Simon Peyton Jones wrote:
|  > When I say
|  >
|  > cabal install
|  > --with-ghc=/home/simonpj/5builds/HEAD-2/inplace/bin/ghc-stage2
|  >
|  > I get this
|  >
|  > ghc-stage2: ghc no longer supports single-file style package
|  databases
|  > (dist/package.conf.inplace) use 'ghc-pkg init' to create the
|  database
|  > with the correct format.
|  >
|  > Now, this is an old build tree, and I could blow it away entirely,
|  but
|  > maybe there is something else going on.  What should I do?
|  
|  What does `cabal --version` say? If it doesn't say something like
|  
|    $ cabal --version
|    cabal-install version 1.21.1.0
|    using version 1.21.1.0 of the Cabal library
|  
|  you probably need a newer one (in which case you should build the
|  `cabal` binary from Git, and to make life easier compile `Cabal` and
|  `cabal-install` with GHC 7.8.x rather than GHC HEAD)
|  
|  Cheers,
|    hvr