From 5dd41be4196c5cd3dfd0acb6c3fcb260e5ed2718 Mon Sep 17 00:00:00 2001
From: Kate <kit.ty.kate@disroot.org>
Date: Mon, 14 Oct 2019 13:36:10 +0100
Subject: [PATCH] Only call opam depext on the packages being tested if it
 contains some depexts

Mitigate ocaml/opam-depext#121
---
 service/opam_build.ml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/service/opam_build.ml b/service/opam_build.ml
index 39962d96..06ec093c 100644
--- a/service/opam_build.ml
+++ b/service/opam_build.ml
@@ -64,14 +64,14 @@ let dockerfile ~base ~info ~repo =
     if Analyse.Analysis.is_duniverse info then Printf.sprintf "%s %s" download_cache (build_cache repo)
     else download_cache
   in
-  let pkgs = get_opam_packages groups |> String.concat " " in
+  let pkgs = get_opam_packages groups in
   let open Dockerfile in
   comment "syntax = docker/dockerfile:experimental" @@
   from (Docker.Image.hash base) @@
   workdir "/src" @@
   run "sudo chown opam /src" @@
   pin_opam_files groups @@
-  run "%s opam install %s --dry-run --deps-only -ty | awk '/-> installed/{print $3}' | xargs opam depext -iy" download_cache pkgs @@
-  run "opam depext -ty %s" pkgs @@
+  run "%s opam install %s --dry-run --deps-only -ty | awk '/-> installed/{print $3}' | xargs opam depext -iy" download_cache (pkgs |> String.concat " ") @@
+  List.fold_left (fun acc pkg -> acc @@ run {|test "$(opam show -f depexts: %s)" = "$(printf "\n")" || opam depext -ty %s|} pkg pkg) empty pkgs @@
   copy ~chown:"opam" ~src:["."] ~dst:"/src/" () @@
   run "%s opam install -tv ." caches