redirect git stderr to /dev/null

Signed-off-by: Rudi Grinberg <[email protected]>

Author: rgrinberg

src/dune_engine/vcs.ml

@@ -86,6 +86,7 @@ let run_git t args =
   let res =
     Process.run_capture (git_accept ()) (prog t) args ~dir:t.root
       ~env:Env.initial
+      ~stderr_to:(Process.Io.file Config.dev_null Out)
   in
   let open Fiber.O in
   let+ res = res in

test/blackbox-tests/test-cases/github4429.t

@@ -18,6 +18,4 @@ Create a repository with no HEAD commit:
 At the moment Dune fails, which is bad:
 
   $ dune exec ./main.exe 2>&1 | sed 's/.*\/git/{{ git }}/; s/> .*.output/> {{ output_file }}/g' 
-           git (internal)
-  fatal: bad revision 'HEAD'