1 files changed, 16 insertions, 0 deletions
diff --git a/nixpkgs/pkgs/development/beam-modules/mix-release.nix b/nixpkgs/pkgs/development/beam-modules/mix-release.nix
index 0b7229a21b5a..1d40da27ecba 100644
--- a/nixpkgs/pkgs/development/beam-modules/mix-release.nix
+++ b/nixpkgs/pkgs/development/beam-modules/mix-release.nix
@@ -9,15 +9,25 @@
 , enableDebugInfo ? false
 , mixEnv ? "prod"
 , compileFlags ? [ ]
+
   # mix fixed output derivation dependencies
 , mixFodDeps ? null
+
   # mix dependencies generated by mix2nix
   # this assumes each dependency is built by buildMix or buildRebar3
   # each dependency needs to have a setup hook to add the lib path to $ERL_LIBS
   # this is how mix will find dependencies
 , mixNixDeps ? { }
+
 , elixir ? inputs.elixir
 , hex ? inputs.hex.override { inherit elixir; }
+
+# This reduces closure size, but can lead to some hard to understand runtime
+# errors, so use with caution. See e.g.
+# https://github.com/whitfin/cachex/issues/205
+# https://framagit.org/framasoft/mobilizon/-/issues/1169
+, stripDebug ? false
+
 , ...
 }@attrs:
 let
@@ -25,6 +35,8 @@ let
   overridable = builtins.removeAttrs attrs [ "compileFlags" "mixNixDeps" ];
 in
 assert mixNixDeps != { } -> mixFodDeps == null;
+assert stripDebug -> !enableDebugInfo;
+
 stdenv.mkDerivation (overridable // {
   # rg is used as a better grep to search for erlang references in the final release
   nativeBuildInputs = nativeBuildInputs ++ [ erlang hex elixir makeWrapper git ripgrep ];
@@ -116,6 +128,10 @@ stdenv.mkDerivation (overridable // {
         substituteInPlace "$file" --replace "${erlang}/lib/erlang" "$out"
       done
     fi
+  '' + lib.optionalString stripDebug ''
+    # strip debug symbols to avoid hardreferences to "foreign" closures actually
+    # not needed at runtime, while at the same time reduce size of BEAM files.
+    erl -noinput -eval 'lists:foreach(fun(F) -> io:format("Stripping ~p.~n", [F]), beam_lib:strip(F) end, filelib:wildcard("'"$out"'/**/*.beam"))' -s init stop
   '';
 
   # TODO investigate why the resulting closure still has