我正在尝试使用install.package("devtools")安装R（v3.6.1）的devtools软件包。尽管openssl version -a表示已安装LibreSSL 2.8.3，但在找不到openssl时安装失败。操作系统是macOS 10.15.1。
这是控制台日志：
* installing *source* package ‘openssl’ ...
** package ‘openssl’ successfully unpacked and MD5 sums checked
** using staged installation
Homebrew 2.2.0
Homebrew/homebrew-core (git revision 434f; last commit 2019-12-03)
Homebrew/homebrew-cask (git revision deedf; last commit 2019-12-03)
Using PKG_CFLAGS=-I/usr/local/opt/[email protected]/include -I/usr/local/opt/openssl/include
------------------------- ANTICONF ERROR ---------------------------
Configuration failed because openssl was not found. Try installing:
* deb: libssl-dev (Debian, Ubuntu, etc)
* rpm: openssl-devel (Fedora, CentOS, RHEL)
* csw: libssl_dev (Solaris)
* brew: [email protected] (Mac OSX)
If openssl is already installed, check that 'pkg-config' is in your
PATH and PKG_CONFIG_PATH contains a openssl.pc file. If pkg-config
is unavailable you can set INCLUDE_DIR and LIB_DIR manually via:
R CMD INSTALL --configure-vars='INCLUDE_DIR=... LIB_DIR=...'
--------------------------------------------------------------------
ERROR: configuration failed for package ‘openssl’
* removing ‘/usr/local/lib/R/3.6/site-library/openssl’
Warning in install.packages :
installation of package ‘openssl’ had non-zero exit status
我如何正确执行该错误消息提示的PATH内容？还是您可以建议其他任何补救方法？ r和macOS安装都是全新的，因此不应有任何与众不同的地方。
由于LibreSSL是OpenSSL的分支，因此我认为它们之间的差异足够大，以至于devtools软件包都无法将其识别为Openssl。您应尝试按照控制台日志的建议安装[email protected]。
brew install openssl