flex-builder -i mkrfs -r yocto:tiny
there are some errors, i can not get yocto-based tiny userland.

~/work/0734/flexbuild_lsdk2012$ flex-builder -i mkrfs -r yocto:tiny
INSTRUCTION: mkrfs
DISTRO TYPE: yocto
DISTRO SCALE: tiny
### Shell environment set up for builds. ###
You can now run 'bitbake <target>'
Common targets are:
core-image-minimal
core-image-sato
meta-toolchain
meta-ide-support
You can also run generated qemu images with a command like 'runqemu qemux86'
Other commonly useful commands are:
- 'devtool' and 'recipetool' handle common recipe tasks
- 'bitbake-layers' handles common layer tasks
- 'oe-pkgdata-util' handles common target package tasks
Loading cache: 100% |#######################################################################################################################################| Time: 0:00:00
Loaded 1305 entries from dependency cache.
Parsing recipes: 100% |#####################################################################################################################################| Time: 0:00:00
Parsing of 776 .bb files complete (772 cached, 4 parsed). 1305 targets, 59 skipped, 0 masked, 0 errors.
NOTE: Resolving any missing task queue dependencies
Build Configuration:
BB_VERSION = "1.44.0"
BUILD_SYS = "x86_64-linux"
NATIVELSBSTRING = "universal"
TARGET_SYS = "aarch64-poky-linux"
MACHINE = "qemuarm64"
DISTRO = "poky"
DISTRO_VERSION = "3.0.4"
TUNE_FEATURES = "aarch64 armv8a crc"
TARGET_FPU = ""
meta
meta-poky
meta-yocto-bsp = "HEAD:f2eb22a8783f1eecf99bd4042695bab920eed00e"
Initialising tasks: 100% |##################################################################################################################################| Time: 0:00:01
Sstate summary: Wanted 873 Found 0 Missed 873 Current 19 (0% match, 2% complete)
NOTE: Executing Tasks
NOTE: Setscene tasks completed
WARNING: unifdef-native-2.11-r0 do_fetch: Failed to fetch URL http://dotat.at/prog/unifdef/unifdef-2.11.tar.xz, attempting MIRRORS if available
WARNING: libtirpc-native-1.1.4-r0 do_fetch: Failed to fetch URL https://downloads.sourceforge.net/libtirpc/libtirpc-1.1.4.tar.bz2, attempting MIRRORS if available
WARNING: libcap-ng-native-0.7.9-r0 do_fetch: Failed to fetch URL http://people.redhat.com/sgrubb/libcap-ng/libcap-ng-0.7.9.tar.gz, attempting MIRRORS if available
ERROR: libtirpc-native-1.1.4-r0 do_fetch: Fetcher failure: Fetch command export PSEUDO_DISABLED=1; unset _PYTHON_SYSCONFIGDATA_NAME; export DBUS_SESSION_BUS_ADDRESS="unix:path=/run/user/1010/bus"; export PATH="/home/chunxi/work/0734/flexbuild_lsdk2012/packages/rfs/yocto-poky/scripts/native-intercept:/home/chunxi/yoctobuild/tmp/sysroots-uninative/x86_64-linux/usr/bin:/home/chunxi/work/0734/flexbuild_lsdk2012/packages/rfs/yocto-poky/scripts:/home/chunxi/yoctobuild/tmp/work/x86_64-linux/libtirpc-native/1.1.4-r0/recipe-sysroot-native/usr/bin/x86_64-linux:/home/chunxi/yoctobuild/tmp/work/x86_64-linux/libtirpc-native/1.1.4-r0/recipe-sysroot-native/usr/bin:/home/chunxi/yoctobuild/tmp/work/x86_64-linux/libtirpc-native/1.1.4-r0/recipe-sysroot-native/usr/sbin:/home/chunxi/yoctobuild/tmp/work/x86_64-linux/libtirpc-native/1.1.4-r0/recipe-sysroot-native/usr/bin:/home/chunxi/yoctobuild/tmp/work/x86_64-linux/libtirpc-native/1.1.4-r0/recipe-sysroot-native/sbin:/home/chunxi/yoctobuild/tmp/work/x86_64-linux/libtirpc-native/1.1.4-r0/recipe-sysroot-native/bin:/home/chunxi/work/0734/flexbuild_lsdk2012/packages/rfs/yocto-poky/bitbake/bin:/home/chunxi/yoctobuild/tmp/hosttools"; export HOME="/home/chunxi"; /usr/bin/env wget -t 2 -T 30 --passive-ftp --no-check-certificate -P /home/chunxi/yoctobuild/downloads 'https://downloads.sourceforge.net/libtirpc/libtirpc-1.1.4.tar.bz2' --progress=dot -v failed with exit code 4, output:
--2021-07-27 09:27:18-- https://downloads.sourceforge.net/libtirpc/libtirpc-1.1.4.tar.bz2
Resolving downloads.sourceforge.net (downloads.sourceforge.net)... failed: Name or service not known.
wget: unable to resolve host address ‘downloads.sourceforge.net’
ERROR: libtirpc-native-1.1.4-r0 do_fetch: Fetcher failure for URL: 'https://downloads.sourceforge.net/libtirpc/libtirpc-1.1.4.tar.bz2'. Unable to fetch URL from any source.
ERROR: Logfile of failure stored in: /home/chunxi/yoctobuild/tmp/work/x86_64-linux/libtirpc-native/1.1.4-r0/temp/log.do_fetch.21744
ERROR: Task (virtual:native:/home/chunxi/work/0734/flexbuild_lsdk2012/packages/rfs/yocto-poky/meta/recipes-extended/libtirpc/libtirpc_1.1.4.bb:do_fetch) failed with exit code '1'
WARNING: util-linux-native-2.34-r0 do_fetch: Failed to fetch URL https://cdn.kernel.org/pub/linux/utils/util-linux/v2.34/util-linux-2.34.tar.xz, attempting MIRRORS if available
NOTE: Tasks Summary: Attempted 227 tasks of which 157 didn't need to be rerun and 1 failed.
Summary: 1 task failed:
virtual:native:/home/chunxi/work/0734/flexbuild_lsdk2012/packages/rfs/yocto-poky/meta/recipes-extended/libtirpc/libtirpc_1.1.4.bb:do_fetch