package/python: apply unicode config to host build

Currently the host build of Python 2 defaults to narrow unicode (UCS2),
ignoring the BR2_PACKAGE_PYTHON_UCS4 configuration option which may be
set to wide (UCS4).

This results in host and target Python packages which are incompatible
in subtle ways.

For example, installing wheels into the target fails when they are made
with the host python, citing incompatibility (as can be seen by the
package tags which may be "cp27u-manylinux1" instead of
"cp27mu-manylinux1").

Compiling the host Python 2 with the same UCS configuration as the
target ensures that the packages are compatible (and the tags match).

This does not affect Python 3 as support for narrow unicode was
deprecated in version 3.3, see https://www.python.org/dev/peps/pep-0393/

Thanks to Tony Breeds <tony@bakeyournoodle.com> for reporting this.

Signed-off-by: Chris Smart <mail@csmart.io>
[Thomas: add comment in the code.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

diff --git a/package/python/python.mk b/package/python/python.mk
index 7b20434c94c2b8b80964e8ce76a7e5351898c584..281130c68bb5ba8187d2d33fcd2f0ca22a481c2f 100644 (file)
--- a/package/python/python.mk
+++ b/package/python/python.mk
@@ -105,6 +105,9 @@ endif
 
 # Default is UCS2 w/o a conf opt
 ifeq ($(BR2_PACKAGE_PYTHON_UCS4),y)
+# host-python must have the same UCS2/4 configuration as the target
+# python
+HOST_PYTHON_CONF_OPTS += --enable-unicode=ucs4
 PYTHON_CONF_OPTS += --enable-unicode=ucs4
 endif