Unable to upgrade cabal itself

Question

I'm trying to upgrade Cabal on Linux:

$ cabal --version
cabal-install version 1.16.0.2
using version 1.16.0 of the Cabal library

And I get plenty of errors:

$ cabal install cabal cabal-install
.............................

checking for sendfile in sys/socket.h... no
checking for gethostent... yes
checking for accept4... yes
configure: creating ./config.status
config.status: creating network.buildinfo
config.status: creating include/HsNetworkConfig.h
configure: WARNING: unrecognized options: --with-compiler, --with-gcc
Building network-2.6.2.0...
Preprocessing library network-2.6.2.0...
ghc: 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.
Failed to install network-2.6.2.0
Configuring old-locale-1.0.0.7...
Building old-locale-1.0.0.7...
Preprocessing library old-locale-1.0.0.7...
ghc: 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.
Failed to install old-locale-1.0.0.7
Configuring random-1.1...
Building random-1.1...
Preprocessing library random-1.1...
ghc: 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.
Failed to install random-1.1
Configuring stm-2.4.4...
Building stm-2.4.4...
Preprocessing library stm-2.4.4...
ghc: 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.
Failed to install stm-2.4.4
Configuring text-1.2.1.1...
Building text-1.2.1.1...
Preprocessing library text-1.2.1.1...
ghc: 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.
Failed to install text-1.2.1.1
Configuring zlib-0.5.4.2...
Building zlib-0.5.4.2...
Preprocessing library zlib-0.5.4.2...
ghc: 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.
Failed to install zlib-0.5.4.2
cabal: Error: some packages failed to install:
HTTP-4000.2.19 depends on text-1.2.1.1 which failed to install.
cabal-install-1.22.4.0 depends on zlib-0.5.4.2 which failed to install.
mtl-2.2.1 failed during the building phase. The exception was:
ExitFailure 1
network-2.6.2.0 failed during the building phase. The exception was:
ExitFailure 1
network-uri-2.6.0.3 depends on text-1.2.1.1 which failed to install.
old-locale-1.0.0.7 failed during the building phase. The exception was:
ExitFailure 1
old-time-1.1.0.3 depends on old-locale-1.0.0.7 which failed to install.
parsec-3.1.9 depends on text-1.2.1.1 which failed to install.
random-1.1 failed during the building phase. The exception was:
ExitFailure 1
stm-2.4.4 failed during the building phase. The exception was:
ExitFailure 1
text-1.2.1.1 failed during the building phase. The exception was:
ExitFailure 1
zlib-0.5.4.2 failed during the building phase. The exception was:
ExitFailure 1

Answer 1

Most likely what has happened is that you've upgraded GHC, and GHC 7.10 requires Cabal 1.22, otherwise the error ghc: 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. appears. Since you're on Ubuntu you can install cabal-install from the PPA:

sudo apt-add-repository ppa:hvr/ghc
sudo apt-get update && sudo apt-get install cabal-install-1.22

Since the PPA install location is isn't in the PATH you can either add /opt/cabal/1.22/bin to your PATH, or optionally run /opt/cabal/1.22/bin/cabal install cabal if you prefer to have all your Haskell binaries in one location and later uninstall cabal-install with apt-get.

Otherwise there are binaries available at haskell.org.