grc + make + read bash builtin bug reproduction test case

Makefile

.PHONY: help list clean
UID            := $(shell id -u)
interactive    := $(shell [ -t 0 ] && echo 1)


ifeq (1,$(interactive))
	INTERACTIVE_SHELL := true
endif

define set-env
	$(eval SOME_ENV_VAR := $(shell \
	  if [[ -z "$(SOME_ENV_VAR)" ]]; then
	    read -r -p "Enter SOME_ENV_VAR (eg 'bar') (set environment variable SOME_ENV_VAR to skip this prompt): "; \
			echo $$REPLY;
		fi;
	))
	@if [[ -z "$(SOME_ENV_VAR)" ]]; then                                                \
		echo "You must specify SOME_ENV_VAR or set env variable SOME_ENV_VAR !"; \
		false;                                                                      \
	fi;
endef

# Auto-documented Makefile
# Source: http://marmelab.com/blog/2016/02/29/auto-documented-makefile.html
help: ## Shows this generated help info for Makefile targets
	@grep -Eh '^[a-zA-Z_-]+:.*?(## )?.*$$' $(MAKEFILE_LIST) | sort | awk '{ if ( $$0 ~ /^[a-zA-Z_-]+:.*?## ?.*$$/ ) { split($$0,resultArr,/:.*## /) ; printf "\033[36m%-30s\033[0m %s\n", resultArr[1], resultArr[2] } else if ( $$0 ~ /^[a-zA-Z_-]+:.*$$/ ) { split($$0,resultArr,/:.*?/);  printf "\033[36m%-30s\033[0m\n", resultArr[1] } } '

list: ## Just list all Makefile targets without help
	@$(MAKE) -pRrq $(addprefix -f ,$(MAKEFILE_LIST)) : 2>/dev/null | awk -v RS= -F: '/^# File/,/^# Finished Make data base/ {if ($$1 !~ "^[#.]") {print $$1}}' | sort | egrep -v -e '^[^[:alnum:]]' -e '^$@$$' | xargs



test: ## run terraform plan with given parameters
	$(set-env)
	@$(MAKE) SOME_ENV_VAR=$(SOME_ENV_VAR) foo

foo:
	echo "SOME_ENV_VAR is $(SOME_ENV_VAR)"
	echo "INTERACTIVE_SHELL is $(INTERACTIVE_SHELL)"