Use cc as $CC if require_cc has called (#148)

plugins/python-build/bin/python-build

@@ -969,17 +969,20 @@ verify_gcc() {
 }
 
 require_cc() {
-  local cc=("$@")
-  while [ -n "${cc}" ]; do
-    { if [ "${#cc[@]}" -le 1 ]; then
-        "require_${cc}" # display last error
-      else
-        "require_${cc}" 3>/dev/null
-      fi
-    } && return 0
-    cc=("${cc[@]:1}")
-  done
-  return 1
+  local cc="$(command -v "$CC" || command -v "cc" || true)"
+
+  if [ -z "$cc" ]; then
+    { echo
+      colorize 1 "ERROR"
+      echo ": This package must be compiled with cc, but python-build couldn't"
+      echo "find a suitable \`cc\` executable on your system. Please install cc"
+      echo "and try again."
+      echo
+    } >&3
+    return 1
+  fi
+
+  export CC
 }
 
 require_clang() {