From b8ac7799cf94edfb8b6a4e2ba82649501e4c777e Mon Sep 17 00:00:00 2001
From: Yung-Yu Chen <yyc@solvcon.net>
Date: Tue, 16 Jun 2026 22:49:47 +0800
Subject: [PATCH] Run pytest via the build interpreter to fix import failures

`make pytest` used the `py.test-3` launcher, whose shebang may bind to a
different Python than the one that built the extension. Since `_modmesh` is
ABI-tagged for the build interpreter, collection failed with "No module named
'_modmesh'" whenever `py.test-3` resolved to another interpreter.

Default `PYTEST` to "$(WHICH_PYTHON) -m pytest" so the runner matches the
build interpreter. The variable stays overridable.
---
 Makefile | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index 896bf87a..28e16f74 100644
--- a/Makefile
+++ b/Makefile
@@ -81,10 +81,9 @@ else
 endif
 export BUILD_PATH
 
-PYTEST ?= $(shell which py.test-3)
-ifeq ($(PYTEST),)
-	PYTEST := $(shell which pytest)
-endif
+# Test with the build interpreter; an ABI-tagged _modmesh cannot load under a
+# py.test-3 launcher bound to a different Python.
+PYTEST ?= $(WHICH_PYTHON) -m pytest
 ifneq ($(VERBOSE),)
 	PYTEST_OPTS ?= -v -s
 else