'Build failed with error: Error: err >= 0' -- Build.js references non-existent exe

[sb2702]

I just downloaded 1.6.8, and was trying to compile my web-app (which I did several months ago under 1.6.0 or something without issue).

I kept getting this build error:
Build failed with error: Error: err >= 0
Error: err >= 0 at exports._errnoException (util.js:676:20)
at ChildProcess.spawn (child_process.js:973:11)
at Object.exports.spawn (child_process.js:753:9)
at Object.$tint.execute (embed://package/js/build.js:498:39)
at Object.$tint.iconcache (embed://package/js/build.js:422:9)
at Object.eval (embed://package/js/build.js:219:12)
at Object.eval (embed://package/js/build.js:140:139)

Even with the example apps.

Looking through the source, I narrowed the problem down:
Line 354 of https://github.com/trueinteractions/tint/blob/master/tools/compiler.js references 'C:\windows\system32\ie4uinit4.exe' - on my windows xp VM, I only see 'ie4uinit.exe' - Adding a copy of the file, renaming to ie4uinit4.exe duly solves the issue, though now I have a non-fatal clearicon cache warning to figure out.

I'm not sure if it's just my Windows VM, which admittedly uses an old image that's just not supported or whatever, or if someone else has been seeing this.