Auto merge of #5716 - bundler:seg-version-build-metadata, r=indirect

Print build metadata when running `bundle version`

Closes #5049.

Will get all the build metadata into `bundle env` once https://github.com/bundler/bundler/pull/5703 lands, since I don't want conflicts and want to use that code for generating the "tables"

4 files changed, 42 insertions, 1 deletions

diff --git a/lib/bundler.rb b/lib/bundler.rb
index 1228785734..9bcadc381f 100644
--- a/lib/bundler.rb
+++ b/lib/bundler.rb
@@ -13,6 +13,7 @@ require "bundler/rubygems_integration"
 require "bundler/version"
 require "bundler/constants"
 require "bundler/current_ruby"
+require "bundler/build_metadata"
 
 module Bundler
   environment_preserver = EnvironmentPreserver.new(ENV, EnvironmentPreserver::BUNDLER_KEYS)
diff --git a/lib/bundler/build_metadata.rb b/lib/bundler/build_metadata.rb
new file mode 100644
index 0000000000..54436f982d
--- /dev/null
+++ b/lib/bundler/build_metadata.rb
@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+module Bundler
+  # Represents metadata from when the Bundler gem was built.
+  module BuildMetadata
+    # begin ivars
+    @release = false
+    # end ivars
+
+    # A hash representation of the build metadata.
+    def self.to_h
+      {
+        "Built At" => built_at,
+        "Git SHA" => git_commit_sha,
+        "Released Version" => release?,
+      }
+    end
+
+    # A string representing the date the bundler gem was built.
+    def self.built_at
+      @built_at ||= Time.now.utc.strftime("%Y-%m-%d").freeze
+    end
+
+    # The SHA for the git commit the bundler gem was built from.
+    def self.git_commit_sha
+      @git_commit_sha ||= Dir.chdir(File.expand_path("..", __FILE__)) do
+        `git rev-parse --short HEAD`.strip.freeze
+      end
+    end
+
+    # Whether this is an official release build of Bundler.
+    def self.release?
+      @release
+    end
+  end
+end
diff --git a/lib/bundler/cli.rb b/lib/bundler/cli.rb
index e93fc9529d..0c89e41656 100644
--- a/lib/bundler/cli.rb
+++ b/lib/bundler/cli.rb
@@ -395,7 +395,10 @@ module Bundler
 
     desc "version", "Prints the bundler's version information"
     def version
-      Bundler.ui.info "Bundler version #{Bundler::VERSION}"
+      if ARGV.include?("version")
+        build_info = " (#{BuildMetadata.built_at} commit #{BuildMetadata.git_commit_sha})"
+      end
+      Bundler.ui.info "Bundler version #{Bundler::VERSION}#{build_info}"
     end
     map %w[-v --version] => :version
 
diff --git a/lib/bundler/env.rb b/lib/bundler/env.rb
index 325b96fbfa..333173ac27 100644
--- a/lib/bundler/env.rb
+++ b/lib/bundler/env.rb
@@ -14,6 +14,7 @@ module Bundler
 
       out = String.new
       append_formatted_table("Environment", environment, out)
+      append_formatted_table("Bundler Build Metadata", BuildMetadata.to_h, out)
 
       unless Bundler.settings.all.empty?
         out << "\n## Bundler settings\n\n```\n"