Hi,
When I installed Houdini on my Gentoo Linux box I got the same error.
I don't know if this will work for you but here's what I did…..
I opened that houdini.install file in my favorite text editor and jumped to line 681 and remove the word exec on that line. I saved the file and ran setup and houdini installed fine.
If you don't feel like editing to file, maybe try switching to a tshell or Cshell before running setup. I don't know if changing shells will work but it's worth a try

Hope this helps,
/R