Increase resiliency of `runnable_binary` (#1134)

foreign_cc/private/runnable_binary_wrapper.sh

@@ -1,13 +1,5 @@
 #!/usr/bin/env bash
 
-# RUN_UNDER_RUNFILES is set in the "bazel test" environment, where all transitive runfiles are placed into one directory
-# Otherwise, first cd to the runfiles dir for the wrapped executable before searching for shared libraries for the wrapped executable
-if [[ -z $RUN_UNDER_RUNFILES ]]; then
-    SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
-    RUNFILES_DIR=${SCRIPT_DIR}/SH_BINARY_FILENAME.runfiles
-fi
-cd ${RUNFILES_DIR}
-
 # --- begin runfiles.bash initialization v2 ---
 # Copy-pasted from the Bazel Bash runfiles library v2. (@bazel_tools//tools/bash/runfiles)
 set -uo pipefail; f=bazel_tools/tools/bash/runfiles/runfiles.bash
@@ -19,6 +11,15 @@ source "$(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 ---
 
+if [[ ! -d "${RUNFILES_DIR}" ]]; then
+    >&2 echo "RUNFILES_DIR is set to '${RUNFILES_DIR}' which does not exist";
+    exit 1;
+fi
+
+RUNFILES_DIR=$( cd "${RUNFILES_DIR}" ; pwd -P )
+
+cd "${RUNFILES_DIR}"
+
 EXE=EXECUTABLE
 EXE_PATH=$(rlocation "${EXE#external/}")
 
@@ -41,10 +42,13 @@ done < <(find . -name "*${SHARED_LIB_SUFFIX}" -print0)
 
 # Add paths to shared library directories to SHARED_LIBS_DIRS_ARRAY
 SHARED_LIBS_DIRS_ARRAY=()
+if [ ${#SHARED_LIBS_ARRAY[@]} -ne 0 ]; then
     for lib in "${SHARED_LIBS_ARRAY[@]}"; do
         SHARED_LIBS_DIRS_ARRAY+=($(dirname $(realpath $lib)))
     done
+fi
 
+if [ ${#SHARED_LIBS_DIRS_ARRAY[@]} -ne 0 ]; then
     # Remove duplicates from array
     IFS=" " read -r -a SHARED_LIBS_DIRS_ARRAY <<< "$(tr ' ' '\n' <<< "${SHARED_LIBS_DIRS_ARRAY[@]}" | sort -u | tr '\n' ' ')"
 
@@ -54,6 +58,7 @@ for dir in "${SHARED_LIBS_DIRS_ARRAY[@]}"; do
         export ${LIB_PATH_VAR}="$dir":"${!LIB_PATH_VAR}"
     done
     set -u
+fi
 
 cd - &> /dev/null
 exec ${EXE_PATH} "$@"