"cabal install cabal-install" doesn't update cabal version in OSX

Question

I'm a newbie to haskell and cabal, so I'm probably missing something simple.

I updated cabal-install:

sudo cabal install cabal-install
Password:
Resolving dependencies...
Configuring cabal-install-1.22.0.0...
Building cabal-install-1.22.0.0...
Installed cabal-install-1.22.0.0
Updating documentation index

However cabal --version says:

cabal-install version 1.18.0.5
using version 1.18.1.4 of the Cabal library

What happened to cabal-install 1.22.0.0?

score 13 · Accepted Answer · answered Jan 07 '15 at 20:46

There are two ways of making cabal install packages globally. Note that, as a result, cabal may require sudo.

This command will install <PACKAGE> globally:

$ cabal install <PACKAGE> --global

As a more general solution, edit the file ~/.cabal/config and set user-install to False. This will automatically set the --global flag so you can just write cabal install <PACKAGE> without any worry. Here's a snippet of my config file:

...
-- split-objs: False
-- executable-stripping: True
user-install: False
-- package-db:
-- flags:
...

You may also want to set root-cmd to sudo if it's not already, so that cabal will automatically prompt for the root password when it encounters a permission problem.

There's some more info online here.

score 5 · Answer 2 · answered Jan 07 '15 at 19:05

5

I see that there's an updated cabal at ~/Library/Haskell/bin, so I could replace /usr/bin/cabal with a symbolic link to this copy or I could copy this binary to /usr/bin.

I'm still interested if there is a more elegant/canonical way to make sure the new cabal is what gets used by default.

answered Jan 07 '15 at 19:05

daj

6,962
9
45
79

3

It's all determined by your PATH. – ErikR Jan 07 '15 at 19:11
Have a look at these answers: http://stackoverflow.com/a/21200691/3649209, http://stackoverflow.com/a/19736802/3649209. – James Lawson Mar 06 '15 at 16:50

score 2 · Answer 3 · answered Oct 28 '15 at 00:34

2

TLDR: Try running hash -r

Bash has a PATH hashtable that maps commands to the location of binaries. You may still have an old version of cabal installed somewhere in your PATH (possibly in a sandbox). Since cabal is not a new command, the hashtable will keep serving up the old version. hash -r rebuilds the hashtable, so the shell will correctly find the new version (providing it appears earlier in your path than the old one).

answered Oct 28 '15 at 00:34

eigensheep

160
5

Small nit: `hash -r` *clears* the hash table. It is then rebuilt on a per-command basis each subsequent time an unqualified path is invoked as a command. – BMDan Jun 09 '19 at 17:14

"cabal install cabal-install" doesn't update cabal version in OSX

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