add more debugging code to track down appveyor 259 exit code

Author: pietroalbini

appveyor.yml

@@ -207,7 +207,10 @@ test_script:
   - sh src/ci/init_repo.sh . /c/cache/rustsrc
   - set SRC=.
   - set NO_CCACHE=1
-  - sh src/ci/run.sh
+  # Added this debugging code to try tracking down https://github.com/rust-lang/rust/issues/58160
+  # Replace it with the commented line below after the issue with AppVeyor is fixed
+  - "sh src/ci/run.sh & set ret=%errorlevel% & echo exit code in appveyor.yml: %ret% & exit %ret%"
+#  - sh src/ci/run.sh
 
 on_failure:
   # Dump crash log

src/ci/run.sh

@@ -127,7 +127,7 @@ if [ ! -z "$SCRIPT" ]; then
   set +e
   sh -x -c "$SCRIPT"
   ret=$?
-  echo "script exited with $ret"
+  echo "exit code in src/ci/run.sh: $ret"
   exit $ret
 else
   do_make() {