texmath: workaround to build with GHC 9.12

Formula/t/texmath.rb

@@ -1,6 +1,7 @@
 class Texmath < Formula
   desc "Haskell library for converting LaTeX math to MathML"
   homepage "https://johnmacfarlane.net/texmath.html"
+  # TODO: Check if `aeson` allow-newer workaround can be removed
   url "https://hackage.haskell.org/package/texmath-0.12.8.13/texmath-0.12.8.13.tar.gz"
   sha256 "bb51a51f69d02c7fed411739d61bff62d56865719542bba995c66e5abe96e409"
   license "GPL-2.0-or-later"
@@ -19,11 +20,15 @@ class Texmath < Formula
   depends_on "ghc" => :build
 
   def install
+    # Workaround to build with GHC 9.12, remove after https://github.com/haskell/aeson/pull/1126
+    # is merged and available on Hackage or if `aeson` is willing to provide a metadata revision
+    args = ["--allow-newer=aeson:ghc-prim,aeson:template-haskell"]
+
     system "cabal", "v2-update"
-    system "cabal", "v2-install", *std_cabal_v2_args, "-fexecutable"
+    system "cabal", "v2-install", "--flags=executable", *args, *std_cabal_v2_args
   end
 
   test do
-    assert_match "<mn>2</mn>", pipe_output(bin/"texmath", "a^2 + b^2 = c^2")
+    assert_match "<mn>2</mn>", pipe_output(bin/"texmath", "a^2 + b^2 = c^2", 0)
   end
 end