Old git bad

Makefile

@@ -54,7 +54,7 @@ endif
 # Submodules
 # NOTE: Do not use &> or <<< here. Systems with annoying default shells will throw a fit if you do.
 ifndef IGNORE_SUBMODULE_HEAD
-UNSYNCED_SUBMODULES         := $(shell git config --file .gitmodules --get-regexp path | awk '{ print $$2 }' | while read -r module; do commit="$$(git ls-tree --object-only HEAD "$$module")"; if [ -e "$$module/.git" ] && ! git --git-dir "$$module/.git" --work-tree "$$module" merge-base --is-ancestor "$$commit" HEAD; then printf '%s, ' "$$module"; fi; done | sed -E 's/, $$//')
+UNSYNCED_SUBMODULES         := $(shell git config --file .gitmodules --get-regexp path | awk '{ print $$2 }' | while read -r module; do commit="$$(git ls-tree HEAD "$$module" | awk '{ print $$3 }')"; if [ -e "$$module/.git" ] && ! git --git-dir "$$module/.git" --work-tree "$$module" merge-base --is-ancestor "$$commit" HEAD; then printf '%s, ' "$$module"; fi; done | sed -E 's/, $$//')
 ifneq ($(UNSYNCED_SUBMODULES),)
     $(error The following submodules are out of date: $(UNSYNCED_SUBMODULES). Either run "git submodule update" or set IGNORE_SUBMODULE_HEAD)
 endif