'new-exec ghc -- --interactive' behaves different than 'new-exec ghci'

[hasufell]

Setup:

$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 8.4.4

So current ghc in PATH is 8.4.4.

Project config is set to ghc-8.4.3

Invoking new-exec ghc -- --interactive in the project dir will start ghci-8.4.3 with the 8.4.3 environment file.

Invoking new-exec ghci will try to start ghci-8.4.4 with the 8.4.3 environment file, which fails straight.

These two should do the same, imo.

[fgaz]

The problem is probably here:

cabal/cabal-install/Distribution/Client/CmdExec.hs

Lines 151 to 155 in e5618f9

	let programDb = modifyProgramSearchPath
	(map ProgramSearchPathDir extraPaths ++)
	. pkgConfigCompilerProgs
	. elaboratedShared
	$ buildCtx

pkgConfigCompilerProgs does not include ghci (?)

[hvr]

@fgaz btw, the suggested fix is to add sugar for cabal new-exec ghci to not invoke ghci (because cabal never does does invoke ghci, nor does it need to). Instead, the consistent way to fix/workaround this in a way consistent w/ cabal new-repl (which does not invoke ghci either) is to desugar cabal new-exec ghci into cabal new-exec ghc --interactive

[jneira]

maybe I missing something but there is a plan to fix the bug and it does not sound hard