From 3c89445b6439f3ce7bffc4cf11c6407c39faedc5 Mon Sep 17 00:00:00 2001
From: Matus Valo <matusvalo@users.noreply.github.com>
Date: Thu, 6 Jul 2023 16:55:25 +0200
Subject: [PATCH] BLD: copy `cython_optimize.pxd` to build dir (#18810)

Closes gh-18792

[skip cirrus] [skip circle]

---------

Co-authored-by: Ralf Gommers <ralf.gommers@gmail.com>
---
 scipy/optimize/cython_optimize.pxd         | 2 +-
 scipy/optimize/cython_optimize/meson.build | 1 +
 scipy/optimize/meson.build                 | 8 +++++++-
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/scipy/optimize/cython_optimize.pxd b/scipy/optimize/cython_optimize.pxd
index d5a0bdd758e0..d35f8da68b34 100644
--- a/scipy/optimize/cython_optimize.pxd
+++ b/scipy/optimize/cython_optimize.pxd
@@ -7,5 +7,5 @@
 # support. Changing it causes an ABI forward-compatibility break
 # (gh-11793), so we currently leave it as is (no further cimport
 # statements should be used in this file).
-from .cython_optimize._zeros cimport (
+from scipy.optimize.cython_optimize._zeros cimport (
     brentq, brenth, ridder, bisect, zeros_full_output)
diff --git a/scipy/optimize/cython_optimize/meson.build b/scipy/optimize/cython_optimize/meson.build
index 359ea8418ba3..ee8def39b4d3 100644
--- a/scipy/optimize/cython_optimize/meson.build
+++ b/scipy/optimize/cython_optimize/meson.build
@@ -17,6 +17,7 @@ cy_opt_gen = generator(cython,
   arguments : cython_args,
   output : '@BASENAME@.c',
   depends : [_cython_tree,
+    cython_optimize_pxd,
     _dummy_init_optimize,
     _dummy_init_cyoptimize])
 
diff --git a/scipy/optimize/meson.build b/scipy/optimize/meson.build
index 26458b05cd70..4c5ab798316b 100644
--- a/scipy/optimize/meson.build
+++ b/scipy/optimize/meson.build
@@ -206,10 +206,16 @@ endif
 
 _dummy_init_optimize = fs.copyfile('__init__.py')
 
+# Copying this .pxd file is only needed because of a Cython bug, see
+# discussion on SciPy PR gh-18810.
+cython_optimize_pxd = [
+  fs.copyfile('cython_optimize.pxd'),
+]
+
 opt_gen = generator(cython,
   arguments : cython_args,
   output : '@BASENAME@.c',
-  depends : [_cython_tree, cython_blas_pxd, _dummy_init_optimize])
+  depends : [_cython_tree, cython_blas_pxd, cython_optimize_pxd, _dummy_init_optimize])
 
 _bglu_dense_c = opt_gen.process('_bglu_dense.pyx')