CC_CLANG_BACKEND not reconfigured during bindist install
- build GHC is built on a machine with clang -- project.mk ends up with the macro
- make binary-dist on that machine
- bring that bindist to a machine that doesn't use clang
- unpack the bindist, ./configure, make install
This error ensues:
cc1: error: unrecognized command line option "-Wno-invalid-pp-token"
cc1: error: unrecognized command line option "-Wno-unicode"
The problem rests in that there is on gcc invocation during that make install:
/usr/bin/gcc -E ... rts/package.conf.in -o rts/dist/package.conf.install.raw
This call is picking up arguments from RAWCPP_FLAGS, set in mk/config.mk, based on CC_CLANG_BACKEND, set in mk/project.mk... which was computed at build time.
carter has hypothesized that adding the macro FP_CC_LLVM_BACKEND to distrib/configure.ac.in might fix this. In theory that will cause the config file that is bunded into the bindist to recompute the CC_CLANG_BACKEND flag at dist config time. However, this may not work because the only file that emits CC_CLANG_BACKEND is project.mk and that doesn't seem to get re-written during dist time config. -- so something else will be needed.