3 files changed, 31 insertions, 11 deletions
diff --git a/Library/Homebrew/formula_installer.rb b/Library/Homebrew/formula_installer.rb
index 498029d2f..9ab03c11f 100644
--- a/Library/Homebrew/formula_installer.rb
+++ b/Library/Homebrew/formula_installer.rb
@@ -60,7 +60,7 @@ class FormulaInstaller
           exit! 1
         end
       end
-      ignore_interrupts do
+      ignore_interrupts do # because child proc will get it and marshall it back
         write.close
         Process.wait
         data = read.read
diff --git a/Library/Homebrew/test/unittest.rb b/Library/Homebrew/test/unittest.rb
index bfa84bfd9..90d9ecdbc 100755
--- a/Library/Homebrew/test/unittest.rb
+++ b/Library/Homebrew/test/unittest.rb
@@ -30,6 +30,24 @@ MACOS_VERSION=10.6
 Dir.chdir HOMEBREW_PREFIX
 at_exit { HOMEBREW_PREFIX.parent.rmtree }
 
+# for some reason our utils.rb safe_system behaves completely differently 
+# during these tests. This is worrying for sure.
+def safe_system *args
+  Kernel.system *args
+end
+
+class ExecutionError <RuntimeError
+  attr :status
+
+  def initialize cmd, args=[], status=nil
+    super "Failure while executing: #{cmd} #{args*' '}"
+    @status = status
+  end
+end
+
+class BuildError <ExecutionError
+end
+
 require 'test/unit' # must be after at_exit
 require 'extend/ARGV' # needs to be after test/unit to avoid conflict with OptionsParser
 ARGV.extend(HomebrewArgvExtension)
diff --git a/Library/Homebrew/utils.rb b/Library/Homebrew/utils.rb
index e30512ff9..d980c328c 100644
--- a/Library/Homebrew/utils.rb
+++ b/Library/Homebrew/utils.rb
@@ -69,27 +69,29 @@ def pretty_duration s
 end
 
 def interactive_shell
-  pid=fork
-  if pid.nil?
+  fork do
     # TODO make the PS1 var change pls
     #brown="\[\033[0;33m\]"
     #reset="\[\033[0m\]"
     #ENV['PS1']="Homebrew-#{HOMEBREW_VERSION} #{brown}\W#{reset}\$ "
     exec ENV['SHELL']
   end
-  Process.wait pid
-  raise SystemExit, "Aborting due to non-zero exit status" if $? != 0
+  Process.wait
+  unless $?.success?
+    puts "Aborting due to non-zero exit status"
+    exit $?
+  end
 end
 
 # Kernel.system but with exceptions
 def safe_system cmd, *args
   puts "#{cmd} #{args*' '}" if ARGV.verbose?
-  exec_success = Kernel.system cmd, *args
-  # some tools, eg. tar seem to confuse ruby and it doesn't propogate the
-  # CTRL-C interrupt to us too, so execution continues, but the exit code is
-  # still 2 so we raise our own interrupt
-  raise Interrupt, cmd if $?.termsig == 2
-  raise ExecutionError.new(cmd, args, $?) unless exec_success
+  fork do
+    trap("EXIT") {} # no bt on exit from this short-lived fork
+    exit! 1 unless exec(cmd, *args)
+  end
+  Process.wait
+  raise ExecutionError.new(cmd, args, $?) unless $?.success?
 end
 
 def curl *args