250814.075203.CST [skip ci] add a comment about flang

Author: zaikunzhang

.github/workflows/stress_test_fortran.yml

@@ -27,6 +27,9 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-13, macos-14]
+        # Zaikun 20250814 The flang test (f) is expected to fail with a segfault due to
+        # https://github.com/llvm/llvm-project/issues/88344 . Updating flang may fix it. See
+        # https://github.com/llvm/llvm-project/pull/98457
         compiler: [g, v, s, f, x, d]
         solver: [newuoa, cobyla, lincoa, bobyqa, uobyqa]
         testdim: [large]

fortran/tests/makefiles/Makefile.common

@@ -406,6 +406,11 @@ ifeq ($(TESTDIM),small)
 	FFORT := $(FFORT) -fstack-arrays
 else
 	FFORT := $(FFORT) -fno-stack-arrays -mmlir -fdynamic-heap-array
+	# As of flang-new version 19.0.0, the above options do not guarantee that the arrays are allocated
+	# on the heap. Segfaults may still occur if the arrays are large enough. See
+	# https://github.com/llvm/llvm-project/issues/88344
+	# Updating flang may fix the issue. See
+	# https://github.com/llvm/llvm-project/pull/98457
 endif
 FFORT := $(FFORT) -std=f2018 -pedantic  # As of flang 19.0, only -std=f2018 is supported
 ifeq ($(OSTYPE),LINUX)