After upgrading to GHC7, all programs suddenly fail saying "Most RTS options are disabled. Link with -rtsopts to enable them."

Question

Haskell tools compiled in the upgraded environment fail with this message, regardless of command line parameters.

Answer 1

As it turns out, RTS options can pose a security issue, so they can be disabled in GHC7. Then, when a RTS option is passed to such a program, it fails.

The problem was that I had GHCRTS environment variable set, which is added to RTS options of all Haskell programs. Clearing this environment variable solved the issue.