
If HOMEBREW_KEEP_INFO environment variable is set: - Do not symlink the info directory file (aka 'share/info/dir') otherwise it gets overwritten by next installed brew. - Install an entry in the directory for each linked info file when the brew is linked. - Uninstall the entry when the brew is unlinked. Closes Homebrew/homebrew#9700. Signed-off-by: Jack Nagel <jacknagel@gmail.com>