WIP Pass cc_wrapper its path via env var

The inherited RUNFILES_* environment variables aren't correct. Pass in a
path to try and find the correct directory/manifest. Only prints
currently.

Author: iteratee

haskell/cc.bzl

@@ -147,6 +147,7 @@ def cc_interop_info(ctx, override_cc_toolchain = None):
         env["CC_WRAPPER_PLATFORM"] = "linux"
 
     env["CC_WRAPPER_CC_PATH"] = real_cc_path
+    env["CC_WRAPPER_PATH"] = cc_wrapper.executable.path
     env["CC_WRAPPER_CPU"] = cc_toolchain.cpu
 
     cc_libraries_info = deps_HaskellCcLibrariesInfo(

haskell/private/cc_wrapper.py.tpl

@@ -1019,6 +1019,8 @@ def run_cc_print_file_name(filename, args):
 
 def find_cc():
     """Find the path to the actual compiler executable."""
+    if "CC_WRAPPER_PATH" in os.environ:
+        print("CC_WRAPPER_PATH: {}".format(os.environ["CC_WRAPPER_PATH"]))
     if os.path.isfile(CC):
         cc = CC
     else:
@@ -1035,6 +1037,7 @@ def find_cc():
             sys.stderr.write("CC not found '{}'.\n".format(CC))
             sys.exit(1)
 
+    print("find_cc returning: {}".format(cc))
     return cc