Pass command and arg list into ErrorDuringExecution constructor

Library/Homebrew/cmd/update.rb

@@ -222,7 +222,7 @@ class Updater
     out = super
     if $? && !$?.success?
       $stderr.puts out
-      raise ErrorDuringExecution, "Failure while executing: #{cmd}"
+      raise ErrorDuringExecution.new(cmd)
     end
     ohai(cmd, out) if ARGV.verbose?
     out

Library/Homebrew/exceptions.rb

@@ -214,7 +214,12 @@ end
 class CurlDownloadStrategyError < RuntimeError; end
 
 # raised by safe_system in utils.rb
-class ErrorDuringExecution < RuntimeError; end
+class ErrorDuringExecution < RuntimeError
+  def initialize(cmd, args=[])
+    args = args.map { |a| a.to_s.gsub " ", "\\ " }.join(" ")
+    super "Failure while executing: #{cmd} #{args}"
+  end
+end
 
 # raised by Pathname#verify_checksum when "expected" is nil or empty
 class ChecksumMissingError < ArgumentError; end

Library/Homebrew/patch.rb

@@ -66,8 +66,9 @@ class EmbeddedPatch
 
   def apply
     data = contents.gsub("HOMEBREW_PREFIX", HOMEBREW_PREFIX)
-    IO.popen("/usr/bin/patch -g 0 -f -#{strip}", "w") { |p| p.write(data) }
+    cmd, args = "/usr/bin/patch", %W[-g 0 -f -#{strip}]
-    raise ErrorDuringExecution, "Applying DATA patch failed" unless $?.success?
+    IO.popen("#{cmd} #{args.join(" ")}", "w") { |p| p.write(data) }
+    raise ErrorDuringExecution.new(cmd, args) unless $?.success?
   end
 
   def inspect

Library/Homebrew/utils.rb

@@ -127,10 +127,7 @@ end
 
 # Kernel.system but with exceptions
 def safe_system cmd, *args
-  unless Homebrew.system cmd, *args
+  Homebrew.system(cmd, *args) or raise ErrorDuringExecution.new(cmd, args)
-    args = args.map{ |arg| arg.to_s.gsub " ", "\\ " } * " "
-    raise ErrorDuringExecution, "Failure while executing: #{cmd} #{args}"
-  end
 end
 
 # prints no output