Use GCC for build ... the object files are compat with clang FFS

Formula/gerbil-scheme.rb

@@ -3,27 +3,19 @@ class GerbilScheme < Formula
   desc "Opinionated dialect of Scheme designed for Systems Programming"
   homepage "https://cons.io"
   url "https://github.com/mighty-gerbils/gerbil.git",
-      using: :git, revision: "92b1a2f642d6ebbcd3bd223ccc0af7ec0d9a42ad"
+      using: :git, revision: "c5546da0bfdc3aa17c66fe1307038bc727ed0816"
   version "0.18.1"
   license any_of: ["LGPL-2.1-or-later", "Apache-2.0"]
-  # revision 3
+  revision 1
   head "https://github.com/mighty-gerbils/gerbil.git", using: :git, branch: "master"
 
-  bottle do
-    root_url "https://github.com/mighty-gerbils/homebrew-gerbil/releases/download/gerbil-scheme-0.18.1"
-    sha256 arm64_sonoma: "58175d28302fde3403f454ecec5ffa76edd9c452d3f97d0060f39300c7ef3aae"
-    sha256 ventura:      "0c432f016e9c0e0ec0324f655a63fd3a90633fc9f77b18a693125b49c08a9fee"
-    sha256 monterey:     "f2a1d37c331248b88762ece4a0c0b57b2c6efdd2012be69cb526352b64df594f"
-    sha256 x86_64_linux: "748cd86ebcba934e24aeafef7b5ee0b0b5b94ee24823a6e3cbb13f17aae6ed11"
-  end
-
   depends_on "coreutils" => :build
   depends_on "pkg-config" => :build
   depends_on "openssl@3"
   depends_on "sqlite"
   depends_on "zlib"
   on_macos do
-    depends_on "llvm"
+    depends_on "gcc@13"
   end
   on_linux do
     depends_on "gcc@13"
@@ -32,22 +24,29 @@ class GerbilScheme < Formula
     version "12" # Select new gcc
     cause "Make it easy with all the same"
   end
+  fails_with :clang do
+    cause "Must be GCC"
+  end
+
   def install
     nproc = `nproc`.to_i - 1
 
     if OS.mac?
-      ENV.prepend_path("PATH", "/usr/local/opt/llvm/bin")
-      ENV.prepend_path("PATH", "/opt/homebrew/opt/llvm/bin")
+      ENV.prepend_path("PATH", "/usr/local/opt/gcc/bin")
+      ENV.prepend_path("PATH", "/opt/homebrew/opt/gcc/bin")
+      ENV["LDFLAGS"] = "-Wl,-ld_classic"
     end
-
     if OS.linux?
       ENV.prepend_path("PATH", "/home/linuxbrew/.linuxbrew/bin")
       ENV.prepend_path("PATH", "/home/linuxbrew/.linuxbrew/sbin")
     end
 
     ENV["GERBIL_GCC"] = ENV.cc.to_s
     ENV["CC"] = ENV.cc.to_s
+    ENV["CXX"] = ENV.cxx.to_s
+    ENV["GERBIL_BUILD_CORES"] = nproc.to_s
 
+    system "echo", ENV.cc.to_s
     system ENV.cc.to_s, "--version"
     system "./configure", "--prefix=#{prefix}", "--enable-march="
     system "make", "-j#{nproc}"

README.org

@@ -6,9 +6,19 @@ brew install mighty-gerbils/gerbil/gerbil-scheme
 
 * How do I install these formulae?
 
-`brew install mighty-gerbils/gerbil/<formula>`
+~brew install mighty-gerbils/gerbil/<formula>~
+
+Or ~brew tap mighty-gerbils/gerbil~ and then ~brew install <formula>~.
+
+** Build the HEAD of Master
+
+Sometimes, like for testing pre-release, we want to build and test the
+lastest commit to the =master= branch.
+
+#+begin_src sh
+brew install mighty-gerbils/gerbil/gerbil-scheme
+#+end_src
 
-Or `brew tap mighty-gerbils/gerbil` and then `brew install <formula>`.
 
 * Documentation
 
@@ -119,10 +129,13 @@ These packages are literate and tangled from this README.org.
 
 * HACKING
 
-Trying to make it work for the github thing means fixing a bunch.
+Trying to make it work for the github thing often means fixing a of
+whitespace and other styles that are frowned upon.
 
-==> brew style --fix  mighty-gerbils/gerbil/gerbil-scheme
 
-brew audit mighty-gerbils/gerbil/gerbil-scheme --online --new
+#+begin_src sh
+brew style --fix  mighty-gerbils/gerbil/gerbil-scheme
 
+brew audit mighty-gerbils/gerbil/gerbil-scheme --online --new
+#+end_src