OpenWRT pylibfdt does not seem to be available with python3

[pkopylov]

I tried to build OpenWRT with package/boot/sunxi-h618.
Here is package Makefile header. Please pay attention it links to this repository commits:

╰─$ head -n 15 Makefile 
#
# Copyright (C) 2013-2016 OpenWrt.org
# Copyright (C) 2017 Yousong Zhou
#
# This is free software, licensed under the GNU General Public License v2.
# See /LICENSE for more information.
#

include $(TOPDIR)/rules.mk
include $(INCLUDE_DIR)/kernel.mk

PKG_SOURCE_PROTO:=git
PKG_SOURCE_URL=https://github.com/orangepi-xunlong/u-boot-orangepi
PKG_SOURCE_DATE:=2024-01
PKG_SOURCE_VERSION:=a4d4b0e24e185e84dd02f06f53999a8effde86db

So during the build process I encountered an error shown below:

if test "/mnt/data/pavel/work/001_OpenWRT/18_sunxi/openwrt/build_dir/target-aarch64_cortex-a53_musl/linux-sunxi_cortexa53/linux-6.1.74/scripts/dtc/dtc" = "./scripts/dtc/dtc"; then \
	make -f ./scripts/Makefile.build obj=scripts/dtc; \
else \
	if ! /mnt/data/pavel/work/001_OpenWRT/18_sunxi/openwrt/build_dir/target-aarch64_cortex-a53_musl/linux-sunxi_cortexa53/linux-6.1.74/scripts/dtc/dtc -v >/dev/null; then \
		echo '*** Failed to check dtc version: /mnt/data/pavel/work/001_OpenWRT/18_sunxi/openwrt/build_dir/target-aarch64_cortex-a53_musl/linux-sunxi_cortexa53/linux-6.1.74/scripts/dtc/dtc'; \
		false; \
	else \
		if test "010601" -lt 010406; then \
			echo '*** Your dtc is too old, please upgrade to dtc 010406 or newer'; \
			false; \
		else \
			if [ -n "y" ]; then \
				if ! echo "import libfdt" | python3 2>/dev/null; then \
					echo '*** pylibfdt does not seem to be available with python3'; \
					false; \
				fi; \
			fi; \
		fi; \
	fi; \
fi
*** pylibfdt does not seem to be available with python3
make[4]: *** [Makefile:2014: scripts_dtc] Error 1
make[4]: Leaving directory '/mnt/data/pavel/work/001_OpenWRT/18_sunxi/openwrt/build_dir/target-aarch64_cortex-a53_musl/u-boot-orangepi_zero3/u-boot-2024-01-a4d4b0e2'
make[3]: *** [Makefile:68: /mnt/data/pavel/work/001_OpenWRT/18_sunxi/openwrt/build_dir/target-aarch64_cortex-a53_musl/u-boot-orangepi_zero3/u-boot-2024-01-a4d4b0e2/.built] Error 2
make[3]: Leaving directory '/mnt/data/pavel/work/001_OpenWRT/18_sunxi/openwrt/package/boot/uboot-sunxi-h618'

The platform I use to build is Ubuntu22.04.

[pkopylov]

It looks like Ubuntu 22.04 issue, which has an old libfdt. To fix the problem, the modern (1.7.0) libfdt should be installed. The farther commands were used to do so:

sudo apt-get install swig python3-dev
sudo apt remove libfdt1
git clone git://git.kernel.org/pub/scm/utils/dtc/dtc.git
cd dtc
make
sudo make install PREFIX=/usr