diff --git a/.github/workflows/workflow.yaml b/.github/workflows/workflow.yaml
index deffceb2b8..922ef8680c 100644
--- a/.github/workflows/workflow.yaml
+++ b/.github/workflows/workflow.yaml
@@ -95,7 +95,7 @@ jobs:
           export PATH=$HOME/bazel:$PATH
           [[ ${{ matrix.os }} == macos ]] && export BAZEL_USE_CPP_ONLY_TOOLCHAIN=1
           ./tests/run-start-script.sh --use-bindists
-          bazel test //tests/...
+          bazel test //tests/... --sandbox_debug
           # Test stack_snapshot pinning
           # NOTE keep in sync with tests/RunTests.hs
           bazel run @stackage-pinning-test-unpinned//:pin
diff --git a/haskell/private/runghc.bzl b/haskell/private/runghc.bzl
index dcd4fe9939..22d680e441 100644
--- a/haskell/private/runghc.bzl
+++ b/haskell/private/runghc.bzl
@@ -34,6 +34,8 @@ source "$(grep -sm1 "^$f " "$0.exe.runfiles_manifest" | cut -f2- -d' ')" 2>/dev/
 {{ echo>&2 "ERROR: cannot find $f"; exit 1; }}; f=; set -e
 # --- end runfiles.bash initialization v2 ---
 
+echo $0.runfiles_manifest 1>&2
+cat $0.runfiles_manifest 1>&2
 $(rlocation "{runghc}") "$@"
 """.format(runghc = runghc_runfile_path),
         is_executable = True,