It’s not often in the (La)TeX world that new versions of things break existing documents and packages. Unfortunately this has just happened to me.
I maintain a LaTeX package pstool (written in collaboration with Zebb Prime) that sort of uses TeX as a portable scripting language to perform external graphics processing during the typesetting run. (The main benefit allowing you to use psfrag in pdfLaTeX.)
Since it executes programs on the command line, it needs to know whether it is being run on Windows or on some sort of *nix variant (Linux, Mac OS X, etc.). The package I use to detect this, ifplatform, is also written by me (in collaboration with Johannes Große), and it uses a heuristic based around the difference in how the shells in Windows/*nix deal with quoted material.
Unfortunately, this heuristic no longer works in TeX Live 2009 for Windows, as reported by Joseph Wright. “That’s okay,” I said, “Few people will be using TeX Live 2009 on Windows yet — no rush to fix the problem immediately.”
Unfortunately again, I’ve now discovered that the problem also exists in MiKTeX 2.8, which has been released in the past week, and which is much more widely used than TeX Live on Windows. I’ve received several good ideas how to fix the problem via the tex-live mailing list, so it just comes down to trying a few of them out with the help of some of my Windows-using friends.
But for now, be warned: ifplatform (v0.2 from 2007) and hence pstool and auto-pst-pdf currently do not work in TeX Live 2009 on Windows and MiKTeX 2.8. A new version to fix this problem will be forthcoming.
Update: The new version of pstool is now available from CTAN, and it fixes the problem above.