Trac #33055: conda-forge: Fix build of python3 spkg

(split out from #32113)

URL: https://trac.sagemath.org/33055
Reported by: mkoeppe
Ticket author(s): Isuru Fernando
Reviewer(s): Matthias Koeppe

build/pkgs/python3/patches/0001-bpo-22699-Allow-compiling-on-debian-ubuntu-with-a-di.patch

@@ -0,0 +1,64 @@
+From aef4a7749dec9ecf942647af39d7a1303c758131 Mon Sep 17 00:00:00 2001
+From: Isuru Fernando <[email protected]>
+Date: Thu, 16 Sep 2021 15:46:09 -0500
+Subject: [PATCH 08/24] bpo-22699: Allow compiling on debian/ubuntu with a
+ different compiler
+
+This PR fixes one issue mentioned in the bpo
+https://bugs.python.org/issue22699#msg364685 with a slightly better
+patch than given
+---
+ setup.py | 19 ++++++++++++++++++-
+ 1 file changed, 18 insertions(+), 1 deletion(-)
+
+diff --git a/setup.py b/setup.py
+index 8fb8ea5c47..783d20bdcd 100644
+--- a/setup.py
++++ b/setup.py
+@@ -663,9 +663,30 @@ def add_multiarch_paths(self):
+         # Debian/Ubuntu multiarch support.
+         # https://wiki.ubuntu.com/MultiarchSpec
+         cc = sysconfig.get_config_var('CC')
+-        tmpfile = os.path.join(self.build_temp, 'multiarch')
+         if not os.path.exists(self.build_temp):
+             os.makedirs(self.build_temp)
++
++        tmpfile_sysroot = os.path.join(self.build_temp, 'sysroot')
++        ret_sysroot = run_command(
++            '%s -print-sysroot > %s 2> /dev/null' % (cc, tmpfile_sysroot))
++
++        try:
++            if ret_sysroot == 0:
++                with open(tmpfile_sysroot) as fp:
++                    sysroot = fp.readline().strip()
++                    # if the sysroot is not /, then we are not using
++                    # the compiler from debian/ubuntu
++                    if sysroot not in ['', '/']:
++                        add_dir_to_list(self.compiler.library_dirs,
++                            sysroot + '/usr/lib')
++                        add_dir_to_list(self.compiler.include_dirs,
++                            sysroot + '/usr/include')
++                        return
++        finally:
++            os.unlink(tmpfile_sysroot)
++
++        tmpfile = os.path.join(self.build_temp, 'multiarch')
++
+         ret = run_command(
+             '%s -print-multiarch > %s 2> /dev/null' % (cc, tmpfile))
+         multiarch_path_component = ''
+--- a/setup.py    2021-09-28 23:49:53.193868987 -0700
++++ b/setup.py    2021-09-28 23:50:13.554098642 -0700
+@@ -738,7 +738,8 @@
+         for env_var, arg_name, dir_list in (
+                 ('LDFLAGS', '-R', self.compiler.runtime_library_dirs),
+                 ('LDFLAGS', '-L', self.compiler.library_dirs),
+-                ('CPPFLAGS', '-I', self.compiler.include_dirs)):
++                ('CPPFLAGS', '-I', self.compiler.include_dirs),
++                ('CPPFLAGS', '-isystem', self.compiler.include_dirs)):
+             env_val = sysconfig.get_config_var(env_var)
+             if env_val:
+                 parser = argparse.ArgumentParser()
+-- 
+2.30.2
+

build/pkgs/python3/spkg-build.in

@@ -90,7 +90,7 @@ sdh_configure --enable-shared $PYTHON_CONFIGURE
 # we need to provide paths into $SAGE_LOCAL, so that setup.py finds
 # the libraries needed for the extension modules - in particular sqlite3.
 # (The search code there does not know about CPATH and LIBRARY_PATH.)
-make_LDFLAGS="-L. -L$SAGE_LOCAL/lib $LDFLAGS"
+make_LDFLAGS="-L. -Wl,-rpath,. -L$SAGE_LOCAL/lib $LDFLAGS"
 make_CPPFLAGS="-I$SAGE_LOCAL/include $CPPFLAGS"
 
 # Also, we need to add an rpath, like we do for SAGE_LOCAL in src/bin/sage-env.