Cabal ad GHC_PACKAGE_PATH

[david larsson]

Im having trouble using Cabal to install a Haskell package.

cabal install xmobar
cabal: Use of GHC's environment variable GHC_PACKAGE_PATH is 
incompatible with
Cabal. Use the flag --package-db to specify a package database (it can 
be used
multiple times).

The archived answers in help-guix didn't work for me, such as "unset 
GHC_PACKAGE_PATH" and then installing which only led to failed builds, 
e.g.:

text-1.2.2.2 failed during the configure step. The exception was:
user error ('/run/current-system/profile/bin/ghc' exited with an error:
/run/current-system/profile/bin/ld: cannot find crt1.o: No such file or
directory
/run/current-system/profile/bin/ld: cannot find crti.o: No such file or
directory
collect2: error: ld returned 1 exit status
)

I also tried to specify the package-db as suggested with a path from the 
GHC_PACKAGE_PATH but this had the same output as if running without that 
flag.

Any suggestions?