fix getpgid issue on aix

2 files changed, 8 insertions, 3 deletions

diff --git a/lib/mixlib/shellout/unix.rb b/lib/mixlib/shellout/unix.rb
index be2e66a..bd9169f 100644
--- a/lib/mixlib/shellout/unix.rb
+++ b/lib/mixlib/shellout/unix.rb
@@ -305,7 +305,10 @@ module Mixlib
           # support the "ONESHOT" optimization (where sh -c does exec without
           # forking). To support cleaning up all the children, we need to
           # ensure they're in a unique process group.
-          Process.setsid
+          # We cannot use setsid here since getpgid fails on AIX with EPERM 
+          # when parent and child have different sessions and the parent tries to get the process group,
+          # hence we just create a new process group, and have the same session.
+          Process.setpgrp
 
           configure_subprocess_file_descriptors
 
diff --git a/spec/mixlib/shellout_spec.rb b/spec/mixlib/shellout_spec.rb
index ff493c2..3a86c20 100644
--- a/spec/mixlib/shellout_spec.rb
+++ b/spec/mixlib/shellout_spec.rb
@@ -940,7 +940,7 @@ describe Mixlib::ShellOut do
         let(:cmd) { [ 'exit' ] }
 
         it "handles ESRCH from getpgid of a zombie", :unix_only do
-          Process.stub(:setsid) { exit!(4) }
+          Process.stub(:setpgrp) { exit!(4) }
 
           # there is a small race condition here if the child doesn't get
           # scheduled and call exit! before the parent can call getpgid, so run
@@ -1074,7 +1074,9 @@ describe Mixlib::ShellOut do
               shell_cmd.stdout.should include("got term in child")
               shell_cmd.stdout.should include("got term in grandchild")
 
-              Process.kill(:INT, child_pgid) # should raise ESRCH
+              kill_return_val = Process.kill(:INT, child_pgid) # should raise ESRCH
+              # AIX - kill returns code > 0 for error, where as other platforms return -1. Ruby code signal.c treats < 0 as error and raises exception and hence fails on AIX. So we check the return code for assertions since ruby wont raise an error here.
+              raise "ESRCH error in AIX" if kill_return_val != 0
 
               # Debug the failure:
               puts "child pgid=#{child_pgid.inspect}"