问题
修改PetaLinux工程的配置文件project-spec/meta-user/conf/petalinuxbsp.conf后，编译出现下列错误，报告“ERROR: Failed to create workspace directory”。
hankf@XSZGS4:/proj/hankf/zcu106/v202/zcu106-v202-bsp-proj$ petalinux-build
INFO: Sourcing build tools
[INFO] Building project
[INFO] Sourcing build environment
[INFO] Generating workspace directory
ERROR: Failed to create workspace directory
ERROR: Failed to build project
分析和解决
于是检查PetaLinux工程的编译日志文件build/build.log，搜索其中的ERROR。检查ERROR开始的内容，发现一行“ERROR: ParseError at project-spec/meta-user/conf/petalinuxbsp.conf:69: unparsed line”。说明petalinuxbsp.conf有错误。检查petalinuxbsp.conf，发现PREMIRRORS_prepend缺少了一个结束的引号。恢复PREMIRRORS_prepend的结束引号，PetaLinux工程又能正常编译了。
编译日志文件build/build.log如下：
[INFO] Building project
[INFO] Sourcing build environment
SDK environment now set up; additionally you may now run devtool to perform development tasks.
Run devtool --help for further details.
INFO: Sourcing build tools
### 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
[INFO] Generating workspace directory
NOTE: Starting bitbake server...
ERROR: Unable to start bitbake server (None)
ERROR: Server log for this session (/proj/hankf/zcu106/v202/zcu106-v202-bsp-proj/build/bitbake-cookerdaemon.log):
--- Starting bitbake server pid 43963 at 2020-12-01 07:17:48.614021 ---
ERROR: ParseError at /proj/hankf/zcu106/v202/zcu106-v202-bsp-proj/project-spec/meta-user/conf/petalinuxbsp.conf:69: unparsed line: 'PREMIRRORS_prepend = " git://.*/.* file:///opt/Xilinx/peta/downloads/ ftp://.*/.* file:///opt/Xilinx/peta/downloads/ http://.*/.* file:///opt/Xilinx/peta/downloads/ https://.*/.* file:///opt/Xilinx/peta/downloads/ git://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ ftp://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ http://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ https://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ '
ERROR: ParseError at /proj/hankf/zcu106/v202/zcu106-v202-bsp-proj/project-spec/meta-user/conf/petalinuxbsp.conf:69: unparsed line: 'PREMIRRORS_prepend = " git://.*/.* file:///opt/Xilinx/peta/downloads/ ftp://.*/.* file:///opt/Xilinx/peta/downloads/ http://.*/.* file:///opt/Xilinx/peta/downloads/ https://.*/.* file:///opt/Xilinx/peta/downloads/ git://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ ftp://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ http://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ https://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ '
ERROR: ParseError at /proj/hankf/zcu106/v202/zcu106-v202-bsp-proj/project-spec/meta-user/conf/petalinuxbsp.conf:69: unparsed line: 'PREMIRRORS_prepend = " git://.*/.* file:///opt/Xilinx/peta/downloads/ ftp://.*/.* file:///opt/Xilinx/peta/downloads/ http://.*/.* file:///opt/Xilinx/peta/downloads/ https://.*/.* file:///opt/Xilinx/peta/downloads/ git://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ ftp://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ http://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ https://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ '
ERROR: Unable to start bitbake server (None)
ERROR: Server log for this session (/proj/hankf/zcu106/v202/zcu106-v202-bsp-proj/build/bitbake-cookerdaemon.log):
--- Starting bitbake server pid 43963 at 2020-12-01 07:17:48.614021 ---
ERROR: ParseError at /proj/hankf/zcu106/v202/zcu106-v202-bsp-proj/project-spec/meta-user/conf/petalinuxbsp.conf:69: unparsed line: 'PREMIRRORS_prepend = " git://.*/.* file:///opt/Xilinx/peta/downloads/ ftp://.*/.* file:///opt/Xilinx/peta/downloads/ http://.*/.* file:///opt/Xilinx/peta/downloads/ https://.*/.* file:///opt/Xilinx/peta/downloads/ git://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ ftp://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ http://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ https://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ '
ERROR: ParseError at /proj/hankf/zcu106/v202/zcu106-v202-bsp-proj/project-spec/meta-user/conf/petalinuxbsp.conf:69: unparsed line: 'PREMIRRORS_prepend = " git://.*/.* file:///opt/Xilinx/peta/downloads/ ftp://.*/.* file:///opt/Xilinx/peta/downloads/ http://.*/.* file:///opt/Xilinx/peta/downloads/ https://.*/.* file:///opt/Xilinx/peta/downloads/ git://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ ftp://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ http://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ https://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ '
ERROR: ParseError at /proj/hankf/zcu106/v202/zcu106-v202-bsp-proj/project-spec/meta-user/conf/petalinuxbsp.conf:69: unparsed line: 'PREMIRRORS_prepend = " git://.*/.* file:///opt/Xilinx/peta/downloads/ ftp://.*/.* file:///opt/Xilinx/peta/downloads/ http://.*/.* file:///opt/Xilinx/peta/downloads/ https://.*/.* file:///opt/Xilinx/peta/downloads/ git://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ ftp://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ http://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ https://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/ '
ERROR: Failed to build project
结论
PetaLinux工程编译遇到问题时，先看看build/build.log和其它log文件的信息，在检查相关文件，多半能找到解决办法。
其它
petalinuxbsp.conf文件中引起错误的部分，修正如下：
#=============================
#
# https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/60129817/Xilinx+Yocto+Builds+without+an+Internet+Connection
# Xilinx Yocto Builds without an Internet Connection
#
# DL_DIR ?= "${TOPDIR}/downloads"
DL_DIR ?= "/opt/Xilinx/peta/2020.2/downloads"
# SSTATE_DIR ?= "${TOPDIR}/sstate-cache"
SSTATE_DIR ?= "/opt/Xilinx/peta/2020.2/sstate/aarch64"
BB_NO_NETWORK = "1"
# ===============================================
# AR 71798
# https://www.xilinx.com/support/answers/71198.html
PREMIRRORS_prepend = "
git://.*/.* file:///opt/Xilinx/peta/downloads/
ftp://.*/.* file:///opt/Xilinx/peta/downloads/
http://.*/.* file:///opt/Xilinx/peta/downloads/
https://.*/.* file:///opt/Xilinx/peta/downloads/
git://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/
ftp://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/
http://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/
https://.*/.* file:///opt/Xilinx/peta/2020.2/downloads/
"
上述内容，使PetaLinux从本地下载文件，不从网络下载，从而进行离线编译。