Try "type cabal". "which" has a nasty tendency to show you what the next shell you open (or sometimes the next time you login) will see; shells remember what they've already seen, so it's probably still running the old one (likely in /usr/bin or /usr/local/bin). POSIX requires "type" to show what the *current* shell (thinks it) knows, not what some future shell will see.

"hash -r" should work to reset the shell's idea of where cabal is, if "type" says it's running a different cabal.
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