Update install.sh to support bzlmod repo mappings

tools/xcodeproj_shims/BUILD.bazel

@@ -37,6 +37,7 @@ sh_binary(
     srcs = ["install.sh"],
     data = [":installer_runfiles"],
     visibility = STUB_VISIBILITY,
+    deps = ["@bazel_tools//tools/bash/runfiles"],
 )
 
 sh_binary(

tools/xcodeproj_shims/install.sh

@@ -5,6 +5,36 @@
 
 set -eux
 
+# --- begin runfiles.bash initialization v3 ---
+# Copy-pasted from the Bazel Bash runfiles library v3.
+set -uo pipefail; set +e; f=bazel_tools/tools/bash/runfiles/runfiles.bash
+source "${RUNFILES_DIR:-/dev/null}/$f" 2>/dev/null || \
+source "$(grep -sm1 "^$f " "${RUNFILES_MANIFEST_FILE:-/dev/null}" | cut -f2- -d' ')" 2>/dev/null || \
+source "$0.runfiles/$f" 2>/dev/null || \
+source "$(grep -sm1 "^$f " "$0.runfiles_manifest" | cut -f2- -d' ')" 2>/dev/null || \
+source "$(grep -sm1 "^$f " "$0.exe.runfiles_manifest" | cut -f2- -d' ')" 2>/dev/null || \
+{ echo>&2 "ERROR: cannot find $f"; exit 1; }; f=; set -e
+# --- end runfiles.bash initialization v3 ---
+
+# Compute the proper BAZEL_BUILD_TARGET_WORKSPACE when using bzlmod.
+# This is computed via the runfiles API using `runfiles_current_repository`.
+# The repo_mappings file looks like:
+#
+# current_canonical,target_local,target_canonical
+# ,bazel_build_rules_ios,_main
+# ...
+# We are interested in the target_local name from the target_canonical name.
+# For example, if the target_canonical is _main, then the target_local is bazel_build_rules_ios.
+if [[ -f "$RUNFILES_REPO_MAPPING" ]]; then
+    while IFS= read -r line; do
+        IFS=',' read -ra repo_mapping_entry_parts <<<"$line"
+        if [[ "${repo_mapping_entry_parts[2]}" == "${BAZEL_BUILD_TARGET_WORKSPACE}" ]]; then
+            BAZEL_BUILD_TARGET_WORKSPACE="${repo_mapping_entry_parts[1]}"
+            break
+        fi
+    done < "$RUNFILES_REPO_MAPPING"
+fi
+
 # Delete all logfiles that are older than 7 days
 find "${BAZEL_DIAGNOSTICS_DIR}" -type f -atime +7d -delete