While working on reproducible builds for openSUSE, I found that our ocaml-dune package varies through non-determinism from filesystem readdir order.

Expected Behavior

dune build should be reproducible

Actual Behavior

--- strings RPMS.1/usr/bin/dune
+++ strings RPMS.2/usr/bin/dune
[...]
 padding.0
-sha1_do_chunk
 sha512_do_chunk
+sha1_do_chunk
 scanmult
 shutdown_happened

Maybe related: ocaml-dune-3.12.2/_boot/source_files produced by ./.duneboot.exe --verbose also has order variations.

Reproduction

build on two different filesystems or use disorderfs or randomize readdir order

Specifications

• Version of dune (output of dune --version): ocaml-dune-3.12.2 with boot: remove single-command bootstrap #9735
• Version of ocaml (output of ocamlc --version) ocaml-4.14.1
• Operating system (distribution and version): openSUSE Tumbleweed