Cabal fails updating of cabal-install

问题

Every time I install a library, cabal tells me to install a new version of cabal-install. Despite the fact that i run (with apparent success) the procedure that list below, the version of cabal-install remains unchanged. Where I am going wrong? (My OS is Window 7 64-bits)

My User PATH is C:\Users\Alberto\AppData\Roaming\cabal\bin

System variables: CABAL_DIR = C:\Users\Alberto\AppData\Roaming\cabal

BEFORE the update

C:\Users\Alberto>cabal -V
cabal-install version 1.16.0.2
using version 1.16.0 of the Cabal library

C:\Users\Alberto>cabal update
Downloading the latest package list from hackage.haskell.org
Note: there is a new version of cabal-install available.
To upgrade, run: cabal install cabal-install

C:\Users\Alberto>cabal install cabal-install

AFTER the update

Linking dist\build\cabal\cabal.exe ...
Installing executable(s) in C:\Users\Alberto\AppData\Roaming\cabal\bin
Installed cabal-install-1.18.0.2

C:\Users\Alberto>cabal -V
cabal-install version 1.16.0.2
using version 1.16.0 of the Cabal library

But:

C:\Users\Alberto>C:\Users\Alberto\AppData\Roaming\cabal\bin\cabal.exe -V
cabal-install version 1.18.0.2
using version 1.18.1.2 of the Cabal library

I am very confused about.

回答1:

What's the output of C:\Users\Alberto\AppData\Roaming\cabal\bin\cabal.exe -V?

回答2:

You probably just need to set your PATH to make sure that C:\Users\Alberto\AppData\Roaming\cabal\bin is at/near the beginning.

You can set this in "Control Panel" -> "System" -> "Advanced System Settings" -> "Advanced" -> "Environment Variables" and then edit the "User variables".

回答3:

What is your $PATH? It seems that you are using a cabal binary from somewhere else than C:\Users\Alberto\AppData\Roaming\cabal\bin, so that one continues to be used when you type cabal.

来源：https://stackoverflow.com/questions/21366775/cabal-fails-updating-of-cabal-install

标签

haskell

cabal-install