From dc5e22511f783391282eca6a986971e6fe6f20b3 Mon Sep 17 00:00:00 2001
From: Matthias Koeppe <mkoeppe@math.ucdavis.edu>
Date: Sat, 30 Jan 2021 20:17:04 -0800
Subject: [PATCH] build/pkgs/python3/spkg-configure.m4: On macOS, if the
 distutils test fails, try using empty ARCHFLAGS

---
 build/pkgs/python3/spkg-configure.m4 |  6 +++++-
 m4/sage_check_python_for_venv.m4     | 19 +++++++++++++++++--
 src/bin/sage-env                     |  6 +++---
 src/bin/sage-env-config.in           |  2 +-
 4 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/build/pkgs/python3/spkg-configure.m4 b/build/pkgs/python3/spkg-configure.m4
index f1470e904d4..40880ffa2d2 100644
--- a/build/pkgs/python3/spkg-configure.m4
+++ b/build/pkgs/python3/spkg-configure.m4
@@ -75,10 +75,14 @@ SAGE_SPKG_CONFIGURE([python3], [
     dnl POST
     AS_IF([test x$sage_spkg_install_python3 = xno], [
         PYTHON_FOR_VENV="$ac_cv_path_PYTHON3"
+        AS_IF([test "$SAGE_ARCHFLAGS" != "unset"], [
+            ARCHFLAGS="$SAGE_ARCHFLAGS"
+            export ARCHFLAGS
+        ])
         AS_IF([test -n "$CFLAGS_MARCH"], [
             dnl Trac #31228
             AC_MSG_CHECKING([whether "$CFLAGS_MARCH" works with the C/C++ compilers configured for building extensions for $PYTHON_FOR_VENV])
-            SAGE_PYTHON_CHECK_DISTUTILS([CC="$CC" CXX="$CXX" ARCHFLAGS="" CFLAGS="$CFLAGS_MARCH" conftest_venv/bin/python3], [
+            SAGE_PYTHON_CHECK_DISTUTILS([CC="$CC" CXX="$CXX" CFLAGS="$CFLAGS_MARCH" conftest_venv/bin/python3], [
                 AC_MSG_RESULT([yes])
             ], [
                 AC_MSG_RESULT([no, with these flags, $reason; disabling use of "$CFLAGS_MARCH"])
diff --git a/m4/sage_check_python_for_venv.m4 b/m4/sage_check_python_for_venv.m4
index 89b42106674..64bc1e2da56 100644
--- a/m4/sage_check_python_for_venv.m4
+++ b/m4/sage_check_python_for_venv.m4
@@ -7,6 +7,8 @@ AC_DEFUN([SAGE_CHECK_PYTHON_FOR_VENV], [
                 m4_pushdef([REQUIRED_MODULES], [$4])
                 m4_pushdef([COMMANDS_IF_GOOD], [$5])
 
+                AC_SUBST([SAGE_ARCHFLAGS])
+
                 AC_MSG_CHECKING([... whether ]PYTHON_EXE[ is good])
                 python3_version=`"PYTHON_EXE" --version 2>&1 \
                     | $SED -n -e 's/\([[0-9]]*\.[[0-9]]*\.[[0-9]]*\).*/\1/p'`
@@ -19,10 +21,23 @@ AC_DEFUN([SAGE_CHECK_PYTHON_FOR_VENV], [
                             dnl m4_define([conftest_venv], [config-venv]) .... for debugging only
                             rm -rf conftest_venv
                             AS_IF(["]PYTHON_EXE[" build/bin/sage-venv conftest_venv && conftest_venv/bin/python3 -c "import ]REQUIRED_MODULES["], [
-                                SAGE_PYTHON_CHECK_DISTUTILS([CC="$CC" CXX="$CXX" ARCHFLAGS="" conftest_venv/bin/python3], [
+                                SAGE_PYTHON_CHECK_DISTUTILS([CC="$CC" CXX="$CXX" conftest_venv/bin/python3], [
+                                    SAGE_ARCHFLAGS="unset"
                                     COMMANDS_IF_GOOD
                                 ], [
-                                    AC_MSG_RESULT([no, the version is in the supported range, and the modules can be imported, but $reason])
+                                    AS_CASE([$host],
+                                        [*-*-darwin*], [
+                                            dnl #31227: Try if setting ARCHFLAGS to empty fixes it
+                                            SAGE_PYTHON_CHECK_DISTUTILS([CC="$CC" CXX="$CXX" ARCHFLAGS="" conftest_venv/bin/python3], [
+                                                SAGE_ARCHFLAGS=""
+                                                COMMANDS_IF_GOOD
+                                            ], [
+                                                AC_MSG_RESULT([no, the version is in the supported range, and the modules can be imported, but $reason (even with ARCHFLAGS set to empty)])
+                                            ])
+                                        ], [
+                                            AC_MSG_RESULT([no, the version is in the supported range, and the modules can be imported, but $reason])
+                                        ]
+                                    )
                                 ])
                             ], [
                                 AC_MSG_RESULT([no, the version is in the supported range but cannot import one of the required modules: ]REQUIRED_MODULES)
diff --git a/src/bin/sage-env b/src/bin/sage-env
index 317ed700293..4c617d8cd44 100644
--- a/src/bin/sage-env
+++ b/src/bin/sage-env
@@ -206,9 +206,9 @@ export F95="$FC"
 # If the environment defines ARCHFLAGS, even when empty, then take that.
 # Otherwise, use the configured value; but if that is "unset", do not set
 # the variable at all.
-if [ "{$ARCHFLAGS-unset}" = "unset" ]; then
-    if [ "${CONFIGURED_ARCHFLAGS-unset}" != "unset" ]; then
-        export ARCHFLAGS="${CONFIGURED_ARCHFLAGS}"
+if [ "${ARCHFLAGS-unset}" = "unset" ]; then
+    if [ "${SAGE_ARCHFLAGS-unset}" != "unset" ]; then
+        export ARCHFLAGS="${SAGE_ARCHFLAGS}"
     fi
 fi
 
diff --git a/src/bin/sage-env-config.in b/src/bin/sage-env-config.in
index 2285c7c4035..7ab1995e4e8 100644
--- a/src/bin/sage-env-config.in
+++ b/src/bin/sage-env-config.in
@@ -42,7 +42,6 @@ CONFIGURED_CXX="@CXX@"
 CONFIGURED_FC="@FC@"
 CONFIGURED_OBJC="@OBJC@"
 CONFIGURED_OBJCXX="@OBJCXX@"
-CONFIGURED_ARCHFLAGS="@ARCHFLAGS@"
 
 #######################################
 # Other configuration (exported)
@@ -51,5 +50,6 @@ CONFIGURED_ARCHFLAGS="@ARCHFLAGS@"
 #######################################
 # Other configuration (not exported, only used in sage-env)
 #######################################
+SAGE_ARCHFLAGS="@SAGE_ARCHFLAGS@"
 SAGE_PKG_CONFIG_PATH="@SAGE_PKG_CONFIG_PATH@"
 SAGE_MACOSX_DEPLOYMENT_TARGET="@SAGE_MACOSX_DEPLOYMENT_TARGET@"