I wrote:
I currently have GHC 6.8.2 installed via MacPorts in /opt/local. When I use Cabal to install packages manually, they install into /usr/local... Now, what will happen when I install a second copy of GHC 6.8.2 into /usr/local using the installer? First question: What will --with-compiler=ghc-6.8.2 now mean if I forget to specify the full path?
Duncan Coutts wrote:
It will use whichever is the ghc-6.8.2 on the $PATH.
They'll both be in $PATH. So do you mean the first one? Will that work consistently throughout the install process?
Second question: When I install packages, both copies of GHC 6.8.2 will want to install them into /usr/local. Cabal uses directory names like "ghc-6.8.2" to keep installations for different compilers separate from each other. But what if both of the compilers are called "ghc-6.8.2"?
Then they will clash. Don't do that :-)
Ouch. I was afraid of that. This is going to be tricky.
You can have two instances of the same version of GHC installed (though quite why you'd want to do that I'm not sure)
Well, a MacPorts port and a binary install each have their advantages and disadvantages. (Think ebuild vs. apt/yum/rpm on linux.) It is certainly conceivable that you'd want both, each configured differently. I will definitely need both to coexist at least for a while as I transition from MacPorts back to the binary install when it is ready. Another example: if we adopt Simon's idea of GHC distributions - and I think we should - then we are likely to see several such distributions, tailored for different needs, and some people installing more than one of them. Thanks, Yitz