I believe I have found a solution and am posting the following two links for others who might be driven insane by this problem.
(ghci worked, then didn't, then did, then didn't). Turns out it seems to be ghc's terminal bindings need some work.

http://forums.gentoo.org/viewtopic-t-845199-view-previous.html?sid=93c638d029aac6ffe40df2c6b86684ce

which led me here

http://trac.haskell.org/haskeline/ticket/105

Thank you intarwebs, and haskell-cafe!

tl;dr try changing your TERM environment variable to "xterm".

On Wed, Jan 12, 2011 at 8:18 PM, Michael Litchard <michael@schmong.org> wrote:
ghc-pkg check
seems fine


On Wed, Jan 12, 2011 at 7:47 PM, Paulo Tanimoto <ptanimoto@gmail.com> wrote:
Nothing wrong from:

$ ghc-pkg check

?

On Wed, Jan 12, 2011 at 9:11 PM, Michael Litchard <michael@schmong.org> wrote:
> Oh, and the distro would be Debian (whatever the latest stable is)
>
>
> On Wed, Jan 12, 2011 at 7:10 PM, Michael Litchard <michael@schmong.org>
> wrote:
>>
>> Linux kether 2.6.26-2-xen-amd64 #1 SMP Thu Sep 16 16:32:15 UTC 2010 x86_64
>> GNU/Linux
>>
>>
>> This was working fine for quite awhile, then broke.
>> Also, I already tried removing the .ghc directory
>>
>> On Wed, Jan 12, 2011 at 6:16 PM, Antoine Latter <aslatter@gmail.com>
>> wrote:
>>>
>>> What operating system/cpu are you using?
>>>
>>> On Jan 12, 2011 8:08 PM, "Michael Litchard" <michael@schmong.org> wrote:
>>> > this just started happening, don't know why.
>>> >
>>> > Could anyone offer suggestions, troubleshooting methods?
>>> >
>>> > ghci
>>> > GHCi, version 6.12.3: http://www.haskell.org/ghc/ :? for help
>>> > Loading package ghc-prim ... linking ... done.
>>> > Loading package integer-gmp ... linking ... done.
>>> > Loading package base ... linking ... done.
>>> > Loading package ffi-1.0 ... linking ... done.
>>> > Segmentation fault
>>
>
>
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