meson: Problems switching from numpy.distutils to meson

Describe the bug This is likely not a bug, but rather a lack of understanding on the correct procedures. I’ve been working on this on and off for a bit, and am now stuck and hoping for a bit of help or a shove in a useful direction.

My problem is that I can’t get meson to build my python-wrapped-legacy-fortran on Windows. This works on my local computer (OS X Big Sur). My access to Windows is only through GitHub Actions, and the latest failure can be seen here: https://github.com/aburrell/apexpy/runs/7048848662?check_suite_focus=true

It looks like the compiler isn’t finding the Python.h header. This header exists and meson.build can find it (see the meson build step). I am out of ideas on how to fix this. I also tried using miniconda, but that failed much earlier (in the build step, due to the binutils library version not being new enough to be used with meson and no newer library available).

To Reproduce You can check out the working branch at the public repository: https://github.com/aburrell/apexpy/tree/reorg_w_meson

Expected behavior Meson being able to build and install the code on Windows.

system parameters

Is this a cross build or just a plain native build (for the same computer)? native build
what operating system (e.g. MacOS Catalina, Windows 10, CentOS 8.0, Ubuntu 18.04, etc.): Microsoft Windows Server 2022
what Python version are you using e.g. 3.8.0: Python 3.7.9
what meson --version: meson 0.62.2
what ninja --version if it’s a Ninja build: ninja 1.11.0

About this issue

Original URL
State: closed
Created 2 years ago
Comments: 15 (12 by maintainers)

Most upvoted comments

I’m looking at a local patch for this, it reduces the number of build steps by 22 (down to 1551, which isn’t all that much in proportion).

EDIT: and there’s a 9-line warning it produces.

eli-schwartz on Jun 26, 2022

It is grabbing fortranobject.c from inside numpy.f2py’s installed data directory src/, and adding it to various extension modules all over the tree.

Yep, I think that’s the simplest way for now. I recommend copying https://github.com/scipy/scipy/blob/55fca818b49d5730c3cc77d012a593a910f3c03c/scipy/meson.build#L39-L52, and after that every extension module that uses f2py should have dependencies like https://github.com/scipy/scipy/blob/55fca818b49d5730c3cc77d012a593a910f3c03c/scipy/interpolate/meson.build#L142-L146

It’s entirely possible that in the long run, Meson will handle this in some more integrated fashion. e.g. adding a numpy and/or f2py dependency

Yes, we should do that in some form or another. This is tracked in gh-9598.

rgommers on Jun 26, 2022

The install declarations aren’t quite correct yet either. Here’s a patch that demonstrates how to do it correctly:

From 9a089fe2d89a6dd4f640e6f760e2c43e0631780f Mon Sep 17 00:00:00 2001
From: Eli Schwartz <eschwartz93@gmail.com>
Date: Fri, 24 Jun 2022 18:39:31 -0400
Subject: [PATCH] meson: fully install all files

- extension modules importable as "foo.bar" must be named "bar" and
  installed via `subdir: 'foo'`; naming them "foo.bar" will attempt to
  install a top-level file named "foo.bar.$EXT" which python does not
  know how to import
- install all the pure python sources
---
 meson.build | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/meson.build b/meson.build
index b900624..8d4f86d 100644
--- a/meson.build
+++ b/meson.build
@@ -119,11 +119,25 @@ endif
 # Check the python headers
 cc.check_header('Python.h', dependencies: [py3_dep], required: true)
 
-py3.extension_module('apexpy.fortranapex',
+py3.extension_module('fortranapex',
   'fortranapex/magfld.f', 'fortranapex/apex.f', 'fortranapex/makeapexsh.f90',
   'fortranapex/igrf.f90', 'fortranapex/apexsh.f90',
   'fortranapex/checkapexsh.f90', 'fortranapex/fortranapexmodule.c',
   include_directories: inc_dirs,
   c_args: numpy_nodepr_api,
   dependencies : py3_dep,
+  subdir: 'apexpy',
   install : true)
+
+py3.install_sources(
+  'apexpy/apex.py',
+  'apexpy/apexsh.dat',
+  'apexpy/_copyfiles.py',
+  'apexpy/_gcc_build_bitness.py',
+  'apexpy/helpers.py',
+  'apexpy/igrf13coeffs.txt',
+  'apexpy/__init__.py',
+  'apexpy/__main__.py',
+  pure: false,
+  subdir: 'apexpy'
+)
-- 
2.35.1

eli-schwartz on Jun 24, 2022