Error installing yesod on Haskell Platform 2012.2.0.0 on Windows XP

Question

I trust tried to install yesod using "cabal install yesod-platform" but the installation aborted with the following error:

cabal: Error: some packages failed to install:
 authenticate-1.2.1.1 depends on zlib-conduit-0.4.0.2 which failed to
 install.
 http-conduit-1.4.1.10 depends on zlib-conduit-0.4.0.2 which failed to
 install.
 wai-extra-1.2.0.5 depends on zlib-conduit-0.4.0.2 which failed to install.
 xss-sanitize-0.3.2 failed while unpacking the package. The exception was:
 user error (truncated tar archive)
 yesod-1.0.1.6 depends on zlib-conduit-0.4.0.2 which failed to install.
 yesod-auth-1.0.2.1 depends on zlib-conduit-0.4.0.2 which failed to install.
 yesod-core-1.0.1.2 depends on zlib-conduit-0.4.0.2 which failed to install.
 yesod-default-1.0.1.1 depends on zlib-conduit-0.4.0.2 which failed to
 install.
 yesod-form-1.0.0.4 depends on zlib-conduit-0.4.0.2 which failed to install.
 yesod-json-1.0.0.1 depends on zlib-conduit-0.4.0.2 which failed to install.
 yesod-persistent-1.0.0.1 depends on zlib-conduit-0.4.0.2 which failed to
 install.
 yesod-platform-1.0.5 depends on zlib-conduit-0.4.0.2 which failed to
 install.
 yesod-routes-1.0.1.2 failed while unpacking the package. The exception was:
 user error (truncated tar archive)
 yesod-static-1.0.0.3 depends on zlib-conduit-0.4.0.2 which failed to
 install.
 zlib-conduit-0.4.0.2 failed while unpacking the package. The exception was:
 user error (truncated tar archive)

Any ideas how to fix this problem?

Answer 1

It looks like the zlib-conduit package didn't download properly. Delete the download and try again:

1. find out where your cabal directory is
   1. start ghci
   2. :m System.Directory
   3. getAppUserDataDirectory "cabal"
2. delete the packages\hackage.haskell.org\zlib-conduit subdirectory of your cabal directory
3. run cabal update
4. rerun cabal install yesod-platform

(Step 3 probably isn't needed, but won't hurt.)