Small hacky script to update the CMake version pointed to in build directories created by Homebrew's CMake

brew-cmake-update.rb

#!/usr/bin/env ruby

if ARGV.size < 1 then
  puts "Usage: #{$0} <build-dir>"
  exit
end

build_dir=ARGV[0]
cmake_prefix=File.realpath(`brew --prefix cmake`.strip)
cellar_cmake_path=File.dirname(cmake_prefix)

cache_file="#{build_dir}/CMakeCache.txt"

unless File.exist? cache_file then
  puts "#{build_dir} doesn't look like a CMake build directory"
  exit
end

new_file = File.open("#{cache_file}.new", "w")

File.readlines(cache_file).each do |line|
  if line.match? /.*?=#{cellar_cmake_path}/ then
    line = line.sub(/#{cellar_cmake_path}\/.+?\//, "#{cmake_prefix}/")
  end

  new_file.write(line)
end

new_file.close
File.rename(cache_file, "#{cache_file}.old")
File.rename("#{cache_file}.new", cache_file)

exec("cmake", "-B", build_dir)