rk3568 OpenHarmony 3.1.1 Release 编译(踩坑记)-缺少头文件FlexLexer.h

使用LinuxMint-20.3系统编译OpenHarmony 3.1.1 Release时遇到如下错误：

[OHOS INFO] product_name : , rk3568[OHOS INFO] ERROR at //base/update/updater/services/script/BUILD.gn:23:1: Script returned non-zero exit code.[OHOS INFO] exec_script("//base/update/packaging_tools/code_yacc.py", args)[OHOS INFO] ^----------[OHOS INFO] Current dir: /home/ufo/Openharmony/rk3568/code-v3.1.1-Release/OpenHarmony/out/rk3568/[OHOS INFO] Command: /usr/bin/env /home/ufo/Openharmony/rk3568/code-v3.1.1-Release/OpenHarmony/base/update/packaging_tools/code_yacc.py --scriptname ./bison.sh --output /home/ufo/Openharmony/rk3568/code-v3.1.1-Release/OpenHarmony/base/update/updater/services/script[OHOS INFO] Returned 1 and printed out:[OHOS INFO] [OHOS INFO] ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^[OHOS INFO] [OHOS INFO] stderr:[OHOS INFO] [OHOS INFO] cp: cannot stat '/usr/include/FlexLexer.h': No such file or directory[OHOS INFO] Traceback (most recent call last):[OHOS INFO]   File "/home/ufo/Openharmony/rk3568/code-v3.1.1-Release/OpenHarmony/base/update/packaging_tools/code_yacc.py", line 36, in [OHOS INFO]     PARSE_SCRIPTS = subprocess.check_call([OHOS INFO]   File "/home/ufo/Openharmony/rk3568/code-v3.1.1-Release/OpenHarmony/prebuilts/python/linux-x86/3.9.2/lib/python3.9/subprocess.py", line 373, in check_call[OHOS INFO]     raise CalledProcessError(retcode, cmd)[OHOS INFO] subprocess.CalledProcessError: Command '['./bison.sh']' returned non-zero exit status 1.[OHOS INFO] [OHOS INFO] See //build/ohos/ohos_part.gni:25:16: which caused the file to be included.[OHOS INFO]     _deps += [ get_label_info(module_label, "label_with_toolchain") ][OHOS INFO]  ^--------------------------------------------------[OHOS INFO] is_mmi_have_libinput = true[OHOS INFO] is_mmi_have_hdf = false[OHOS INFO] is_mmi_have_debug = false[OHOS INFO] mmi_enable_combinationkey = true[OHOS INFO] mmi_enable_pointer_drawing = true[OHOS INFO] ---------------------------------------------[OHOS INFO] ccache summary:[OHOS INFO] cache hit (direct)  : 0[OHOS INFO] cache hit (preprocessed)  : 0[OHOS INFO] cache miss  : 0[OHOS INFO] hit rate:  0.00% [OHOS INFO] mis rate: 0.00% [OHOS INFO] ---------------------------------------------[OHOS INFO] file: /home/ufo/Openharmony/rk3568/code-v3.1.1-Release/OpenHarmony/out/rk3568/.ninja_log not exists[OHOS INFO] parse file fail[OHOS ERROR] Please check build log in /home/ufo/Openharmony/rk3568/code-v3.1.1-Release/OpenHarmony/out/rk3568/build.log=====build  error=====

根据错误提示：cp: cannot stat ‘/usr/include/FlexLexer.h’: No such file or directory
大概意思是缺少头文件FlexLexer.h

需要安装相关的依赖包：
sudo apt-get install libfl-dev