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