It's a completely clean jar, downloaded by Forge. Here's the relevant part of the output:
== Reobfuscating server ==
> Cleaning reobf
> Generating md5s
> Packing jar
> Reobfuscating jar
'"java" -cp "runtime/bin/retroguard.jar:lib:lib/*:jars/minecraft_server.jar" RetroGuard -notch temp/s...' failed : 1
== ERRORS FOUND ==
Unrecoverable error during obfuscation, see log file for details.
ERROR: error in opening zip file
==================
FATAL ERROR
Traceback (most recent call last):
File "runtime/reobfuscate.py", line 53, in reobfuscate
reobfuscate_side(commands, SERVER, reobf_all=reobf_all)
File "/Users/abe/mcp/runtime/mcp.py", line 158, in reobfuscate_side
commands.applyrg(side, True)
File "/Users/abe/mcp/runtime/commands.py", line 907, in applyrg
self.runcmd(forkcmd)
File "/Users/abe/mcp/runtime/commands.py", line 1111, in runcmd
raise CalledProcessError(process.returncode, forkcmd, output)
CalledProcessError: Command '"java" -cp "runtime/bin/retroguard.jar:lib:lib/*:jars/minecraft_server.jar" RetroGuard -notch temp/server_ro.cfg' returned non-zero exit status 1
Any ideas? I'm running Python 2.7.2, but I don't think that's important in this case.