Check executable is on a specific path in Makefile - makefile

Question

I want to try and check an executable (in this case Python's pip) is on a specific path (the virtual environment) in the Makefile (this will be done prior to running a make command to install all the requirements, and is a safety measure to ensure they don't end up in system python by mistake).
(Also, yes, I know I can force a virtual env for pip, but this isn't just for me, so I can't guarantee that's done ...)
I've had a few attempts, but currently have this:
DIRENV := $(shell pwd)/.direnv/
PIP := $(shell which pip)
.PHONY: check-pip
check-pip:
FOUND_PIP := $(if $(findstring $(PIP),$(DIRENV)),found,)
$(info FOUND_PIP=$(FOUND_PIP))
ifeq ($(FOUND_PIP),found)
$(info Found pip on the path)
else
$(error ERROR: Cannot find pip))
endif
$(DIRENV) and $(PIP) are correct if I print them out.
There are 2 issues with this:
I can't seem to get findstring to work at all!
The ifeq runs both parts of the conditional regardless.
❯ make check-pip
FOUND_PIP=
Found pip on the path
Makefile:37: *** ERROR: Cannot find pip. Stop.
And just to clarify the make version:
❯ make --version
GNU Make 4.2.1

Answer 1

You have to write your check recipe using shell syntax.
.PHONY: check-pip
check-pip:
case "$(PIP)" in \
("$(DIRENV)"/*) echo "Found pip on the path" ;; \
(*) echo "Cannot find pip"; exit 1 ;; \
esac
Note, you need this if you only want to check this when the user specifically runs the check-pip target.
If you want to check it always whenever the user runs make regardless of which target they specify, then you can use makefile operations but you should not put them in a recipe, because they are run as the makefile is parsed not when a target is built. And you don't need a check-pip target at all.