erlang: work around superenv bug

I don't want to bottle this quite yet since I think a fix in superenv is
imminent.

Fixes #23754.

1 files changed, 8 insertions, 0 deletions

diff --git a/Library/Formula/erlang.rb b/Library/Formula/erlang.rb
index 8f090d803..416175aa8 100644
--- a/Library/Formula/erlang.rb
+++ b/Library/Formula/erlang.rb
@@ -74,6 +74,14 @@ class Erlang < Formula
     end
 
     system "./configure", *args
+
+    if ENV.compiler == :clang
+      # Superenv does not pass -march=native during configure, causing
+      # misdetection of this capability on some architectures:
+      # https://github.com/mxcl/homebrew/issues/23754
+      inreplace Dir['erts/*/config.h'].first, /^#define ETHR_HAVE___SYNC_VAL_COMPARE_AND_SWAP128 1$/, ''
+    end
+
     system "make"
     ENV.j1 # Install is not thread-safe; can try to create folder twice and fail
     system "make install"