fix haskell.org build and rpath issues (#2)

Extreme bunch of work by all of us. In the end it was just a matter of finding the env vars for LDFLAGS for the various stages.

Dang ghc-devs, you hate us.

Co-authored-by: Jonathan Chang <me@jonathanchang.org>
Co-authored-by: Max Howell <mxcl@me.com>

projects/haskell.org/package.yml

@@ -1,5 +1,6 @@
 distributable:
-  url: https://downloads.haskell.org/~ghc/{{ version}}/ghc-{{ version}}-src.tar.xz
+  url: https://downloads.haskell.org/~ghc/{{version}}/ghc-{{version}}-src.tar.xz
+  sig: "{{url}}.sig"
   strip-components: 1
 
 versions:
@@ -9,9 +10,9 @@ versions:
   # strip:
   #   - /^ghc-/
   #   - /-release$/
-
-
-#NOTE relocatable if we edit the shell scripts
+  # however ghc breaks every time they release a new version
+  # so you are welcome to embrace trying to build it, we kindly ask they care
+  # more about ensuring their monolithic nonsense has stability in builds
 
 provides:
   - bin/ghc
@@ -27,7 +28,8 @@ provides:
 dependencies:
   gnu.org/gmp: 6
   invisible-island.net/ncurses: 6
-  tea.xyz/gx/cc: c99  # ghc uses `gcc` as part of its build process
+  tea.xyz/gx/cc: 'c99'  # ghc uses this during builds
+  sourceware.org/libffi: 3
 
 build:
   dependencies:
@@ -36,17 +38,19 @@ build:
     tea.xyz/gx/make: '*'  #FIXME specifically, gnu make is *required*
     curl.se: '*'
     gnu.org/m4: '*'
-  script: |-
-    # `ghc` needs `ghc` to bootstrap `ghc`
-    # The canonical way to achieve this is with `ghcup`
-    # To that end, we capture $HOME so as to no pollute the user's life with unwanted
-    # stage0 tooling. Instead, everything is localized to {{ prefix }}/src, and can be
-    # cleaned up at will, and won't capture any of the user's workflow
+    git-scm.org: ^2
+    python.org: ^3
+    gnu.org/patch: '*'
+    linux:
+      github.com/numactl/numactl: ^2 # ghcup needs this
 
-    export HOME={{ prefix }}/src
-    export BOOTSTRAP_HASKELL_NONINTERACTIVE=1
-    export BOOTSTRAP_HASKELL_ADJUST_BASHRC=0
-    export BOOTSTRAP_HASKELL_GHC_VERSION={{ version }}
+  # `ghc` needs `ghc` to bootstrap `ghc`
+  # The canonical way to achieve this is with `ghcup`
+  # To that end, we capture $HOME so as to no pollute the user's life with unwanted
+  # stage0 tooling. Instead, everything is localized to $HOME, and can be
+  # cleaned up at will, and won't capture any of the user's workflow
+  script: |
+    export HOME="$(pwd)"
 
     if test -d .ghcup; then
       echo "ghcup already installed"
@@ -54,24 +58,49 @@ build:
       curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh
     fi
 
-    PATH="{{ prefix }}/src/.ghcup/bin:$PATH"
+    PATH="$HOME/.ghcup/bin:$PATH"
 
-    if test -e {{ prefix }}/src/.cabal/bin; then
-      rm -r {{ prefix }}/src/.cabal/bin
+    if test -e $HOME/.cabal/bin; then
+      rm -r $HOME/.cabal/bin
     fi
 
-    cabal update && cabal install alex happy
+    cabal update
+    cabal install alex happy
 
-    export PATH="{{ prefix }}/src/.cabal/bin:$PATH"
-    GHC="{{ prefix }}/src/.ghcup/bin/ghc"
+    export PATH="$HOME/.cabal/bin:$PATH"
+    GHC="$HOME/.ghcup/bin/ghc"
 
-    export CPATH=/opt/invisible-island.net/ncurses/v6/include/ncursesw:$CPATH
+    ./configure $ARGS
+    hadrian/build -j --docs=none --prefix="{{prefix}}" install
 
-    #FIXME oddly, they don’t provide `./configure`; we have to generate it
-    autoconf
-    ./configure --prefix={{ prefix }}
-
-    hadrian/build -j install --prefix={{ prefix }} --docs=none
+    for shim in $(find "{{prefix}}/bin" -type f); do
+      sed -i.bak -e 's_="{{prefix}}_="$(dirname $(dirname $0))_' $shim
+      rm $shim.bak
+    done
+  env:
+    BOOTSTRAP_HASKELL_NONINTERACTIVE: 1
+    BOOTSTRAP_HASKELL_ADJUST_BASHRC: 0
+    BOOTSTRAP_HASKELL_GHC_VERSION: ${{version}}
+    CONF_CC_OPTS_STAGE0: $LDFLAGS
+    CONF_CC_OPTS_STAGE1: $LDFLAGS
+    CONF_CC_OPTS_STAGE2: $LDFLAGS
+    CONF_GCC_LINKER_OPTS_STAGE0: $LDFLAGS
+    CONF_GCC_LINKER_OPTS_STAGE1: $LDFLAGS
+    CONF_GCC_LINKER_OPTS_STAGE2: $LDFLAGS
+    ARGS:
+      - --prefix={{prefix}}
+      - --disable-numa
+      - --with-curses-includes={{deps.invisible-island.net/ncurses.prefix}}/include/ncursesw
+      - --with-intree-gmp
+      - --with-system-libffi
+    linux:
+      C_INCLUDE_PATH: ${{deps.invisible-island.net/ncurses.prefix}}/include/ncursesw
+      # ^^ yep telling `./configure` about it just aint enough
+    darwin:
+      ARGS:
+      - --with-ffi-includes=$(xcrun --show-sdk-path)/usr/include/ffi
+      # workaround `fatal error: 'ffitarget_arm64.h' file not found`
+      C_INCLUDE_PATH: $(xcrun --show-sdk-path)/usr/include/ffi
 
 test:
   script: |