Rake executes file task when prerequisites have older timestamp

[satosho]

When a file task depends on some non-file task indirectly,
Rake executes the file task even if its immediate prerequisite files have older timestamp.

It looks like the behavior changed at 12.1.0.

Example

require "rake/clean"

CLEAN.include("config.yml", "component")

task "setup" do
  puts Rake::VERSION
  touch "config.yml" unless File.exist?("config.yml")
end

file "config.yml" => "setup"

file "component" => "config.yml" do |t|
  puts "[config.yml] #{File.mtime(t.prerequisites[0])}"
  puts "[component]  #{File.exist?(t.name) && File.mtime(t.name)}"
  sleep 1
  touch t.name
end

Based on the above Rakefile, clean up and create the "component" first.

$ rake clean && rake component

The next rake component results in different behavior as follows.
On 12.0.0:

$ rake component --trace
(in /path/to/Rakefile-directory)
** Invoke component (first_time, not_needed)
** Invoke config.yml (first_time)
** Invoke setup (first_time)
** Execute setup
12.0.0
** Execute config.yml

On 12.1.0:

$ rake component --trace
(in /path/to/Rakefile-directory)
** Invoke component (first_time)
** Invoke config.yml (first_time)
** Invoke setup (first_time)
** Execute setup
12.1.0
** Execute config.yml
** Execute component
[config.yml] 2018-01-01 15:13:19 +0900
[component]  2018-01-01 15:13:20 +0900
touch component

[grzuy]

I can reproduce the same issue.

Working on a fix for this.

[grzuy]

There's an opened PR attempting to fix this #251

[grzuy]

Second attempt at fixing this one here #257

[chrislo]

Was a fix for this bug ever merged? I've run into it today and it would be great if it could be fixed.

[jgomo3]

Maybe this is precisely the use case of Phony tasks: https://ruby.github.io/rake/doc/rakefile_rdoc.html#label-Phony+Task