无互联网环境下CentOS 7.9安装stringi遇ICU依赖下载失败问题

基础环境说明 #

• 操作系统：CentOS 7.9
• 网络限制：无公网访问权限，仅可连通CRAN软件源
• 离线准备：提前从CRAN下载stringi_1.5.3.tar.gz源码包完成本地解压，解压后目录结构可参考对应附件

安装执行报错详情 #

运行本地源码包安装流程时，终端输出如下连续报错：

checking for pkg-config... /usr/bin/pkg-config
checking with pkg-config for the system ICU4C... 50.2
checking for ICU4C >= 55... no
*** ICU4C 50.2 has been detected
*** Minimal requirements, i.e., ICU4C >= 55, are not met
*** Trying with "standard" fallback flags
checking whether we may build an ICU4C-based project... yes
checking programmatically for sufficient U_ICU_VERSION_MAJOR_NUM... no
*** The available ICU4C cannot be used
checking whether we may compile src/icu61/common/putil.cpp... yes
checking whether we may compile src/icu61/i18n/number_affixutils.cpp... yes
checking whether we can fetch icudt... downloading the ICU data library (icudt)
output path: icu61/data/icudt61l.zip
trying URL 'https://raw.githubusercontent.com/gagolews/stringi/master/src/icu61/data/icudt61l.zip'
Error in download.file(paste(href, fname, sep = ""), icudtzipfname, mode = "wb"): cannot open URL 'https://raw.githubusercontent.com/gagolews/stringi/master/src/icu61/data/icudt61l.zip'

已完成的排查动作 #

• 参照技术社区公开的离线安装指引、stringi官方安装文档开展问题定位
• 尝试执行通用修复命令sed -i '/\/icu..\/data/d' stringi-master/.Rbuildignore调整源码配置，但本地解压的CRAN发布版源码目录中不存在.Rbuildignore文件，无法完成对应配置修改

核心待解决诉求 #

需明确安装流程中download.file函数mode="wb"参数的调整方法，解决无公网环境下无法拉取icudt数据库引发的安装中断问题。 #

内容的提问来源于stack exchange，提问作者maniA