Difficult to cross-compile (e.g. Yocto)

[cmcqueen]

• uvloop version: 0.8.0
• Python version: 3.5.2
• Platform: Cross-compile build using Yocto for BeagleBone Black (ARM)
• Can you reproduce the bug with PYTHONASYNCIODEBUG in env?: N/A

I am trying to make a Yocto bitbake recipe to build uvloop. At the build_ext step it gives an error for the libuv ./configure call, saying for cross-compilation it needs the --host parameter specified.

It might be possible to use the --use-system-libuv option, but at the moment Yocto doesn't support custom options for the build_ext step.

I applied the following patch to work around this:

From 56604f7720089da7d9afd43825fc29f006a0e4bf Mon Sep 17 00:00:00 2001
From: Craig McQueen <craig.mcqueen@innerrange.com>
Date: Thu, 31 Aug 2017 16:31:17 +1000
Subject: [PATCH] Allow for cross-compile of libuv

If HOST_SYS environment variable is defined, then call ./configure with
--host parameter set to HOST_SYS value.
---
 setup.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/setup.py b/setup.py
index ae9a65a..ad474e8 100644
--- a/setup.py
+++ b/setup.py
@@ -226,8 +226,12 @@ class uvloop_build_ext(build_ext):
              'Makefile.am', 'Makefile.in'],
             cwd=LIBUV_BUILD_DIR, env=env, check=True)
 
+        if 'HOST_SYS' in env:
+            cmd = ['./configure', '--host=' + env['HOST_SYS']]
+        else:
+            cmd = ['./configure']
         subprocess.run(
-            ['./configure'],
+            cmd,
             cwd=LIBUV_BUILD_DIR, env=env, check=True)
 
         j_flag = '-j{}'.format(os.cpu_count() or 1)
-- 
2.14.1

But then I had another problem, which is when I tried to import uvloop, I got an error regarding an unresolved symbol pthread_atfork. I used the following patch to resolve this:

From abb18a622d5c3c341fd64da46b243d2734cbe2c8 Mon Sep 17 00:00:00 2001
From: Craig McQueen <craig.mcqueen@innerrange.com>
Date: Thu, 31 Aug 2017 17:25:13 +1000
Subject: [PATCH] Specify pthread library dependency for uvloop.loop extension

---
 setup.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/setup.py b/setup.py
index ad474e8..3eed39e 100644
--- a/setup.py
+++ b/setup.py
@@ -293,6 +293,9 @@ setup(
             sources=[
                 "uvloop/loop.pyx",
             ],
+            libraries=[
+                "pthread",
+            ],
             extra_compile_args=CFLAGS
         ),
     ],
-- 
2.14.1

[cmcqueen]

My Yocto bitbake recipe python3-uvloop_0.8.0.bb is as follows:

DESCRIPTION = "Fast implementation of asyncio event loop on top of libuv"
HOMEPAGE = "https://pypi.python.org/pypi/uvloop"
SECTION = "devel/python"
LICENSE = "MIT & Apache-2.0"
LIC_FILES_CHKSUM = "file://LICENSE-MIT;md5=3bd0b2e751776b370b2151ac508af939 \
                    file://LICENSE-APACHE;md5=dc498442db12459256eff4dcbc80c32f"

FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"

SRCNAME = "uvloop"

SRC_URI = "https://files.pythonhosted.org/packages/source/u/${SRCNAME}/${SRCNAME}-${PV}.tar.gz"

SRC_URI[md5sum] = "279163a7b8f39dc15007cf76e3a92c02"
SRC_URI[sha256sum] = "2c22f1f0b6e00e99f5ee635993e5f26418e740bd26f1214cf78c70f237eec06b"

SRC_URI += "file://0001-Allow-for-cross-compile-of-libuv.patch"
SRC_URI += "file://0001-Specify-pthread-library-dependency-for-uvloop.loop-e.patch"

S = "${WORKDIR}/${SRCNAME}-${PV}"

DEPENDS = "${PYTHON_PN}-cython-native"

BBCLASSEXTEND = "native"

inherit setuptools3

do_compile_prepend() {
    export HOST_SYS=${HOST_SYS}
}

do_install_prepend() {
    export HOST_SYS=${HOST_SYS}
}

I'm currently using Yocto morty branch.

[cmcqueen]

I'm not sure if those patches are suitable for incorporating into the mainline code. If you think they are, I could submit a pull request.

[1st1]

357cb60 should fix the "unresolved symbol pthread_atfork" problem.

[1st1]

Please submit a PR to add HOST_SYS env option. Although I'd rename it to LIBUV_CONFIGURE_HOST.

[1st1]

Will be in the next uvloop release (0.9.0) soon.

[1st1]

Please try uvloop v0.9.0.

[cmcqueen]

I've tried uvloop v0.9.0, and it fixes the two issues nicely. Thanks very much!

[MSezai]

Is there a solution for uvloop_0.20.0.bb ?

when I try to run this in kirkstone:

SUMMARY = "Fast implementation of asyncio event loop on top of libuv"
HOMEPAGE = "http://github.com/MagicStack/uvloop"
LICENSE = "MIT & Apache-2.0"
LIC_FILES_CHKSUM = "file://LICENSE-MIT;md5=489c8bc34154e4b59f5c58e664f7d70f
file://LICENSE-APACHE;md5=bb92739ddad0a2811957bd98bdb90474"

PYPI_PACKAGE = "uvloop"

inherit pypi setuptools3

SRC_URI[md5sum] = "c3395ddc1746e2bf4b2987d88c4707e8"
SRC_URI[sha256sum] = "4603ca714a754fc8d9b197e325db25b2ea045385e8a3ad05d3463de725fdf469"

I get the error:

checking whether we are cross compiling... configure: error: in /home/dev/yocto/build/tmp/work/cortexa7t2hf-neon-vfpv4-poky-linux-gnueabi/python3-uvloop/0.20.0-r0/uvloop-0.20.0/build/libuv-x86_64': | configure: error: cannot run C compiled programs. | If you meant to cross compile, use --host'.

File "/home/dev/yocto/build/tmp/work/cortexa7t2hf-neon-vfpv4-poky-linux-gnueabi/python3-uvloop/0.20.0-r0/recipe-sysroot-native/usr/lib/python3.10/subprocess.py", line 526, in run
| raise CalledProcessError(retcode, process.args,
| subprocess.CalledProcessError: Command '['./configure']' returned non-zero exit status 77.
| ERROR: 'python3 setup.py bdist_wheel ' execution failed.