[bug#53609] [PATCH 2/2] gnu: Add ghc-4.

[Ricardo Wurmus <rekado@elephly.net>]

There had to be a catch, and sure enough: there is one.  This ghc-4
package doesn’t include everything it should.  The good news is that the
RTS of GHC is included.  The bad news is that the standard library
doesn’t exist.

This old build system is a bit too optimistic and will ignore any build
failure.  There are two failures:

--8<---------------cut here---------------start------------->8---
make[3]: *** No rule to make target 'Array.o', needed by 'libHSstd.a'. Stop.
[…]
make[2]: *** No rule to make target 'utils/Argv.o', needed by 'hsc'.  Stop.
--8<---------------cut here---------------end--------------->8---

“Stop.” here is not to be taken literally, it seems.  The build
continues but libHSstd.a doesn’t make it to the finish line.  Array.o
would presumably be built from Haskell code.

This means that the vision I had during a fever dream is still worth
following: combine the GHC RTS with the Hugs interpreter to interpret
the Haskell code of GHC 4 to use it to compile the Haskell code of GHC 4.

-- 
Ricardo