Google shows a couple of hits for this issue, but never a solution that I can find. It's always just a few other people saying "it works for me", and the issue dries up. I've tested both with the "-incremental=true" flag to mxmlc and with the <incremental>true</incremental> tag in my flex config.xml with the same result:
Failed to match the compile target with /export/vampire/build/Editor.swf.cache. The cache file will not be reused.
I get this on each compile after the first that creates the cache, whether the source files were modified or not.
I've checked file permissions (not expecting anything - the cache file and the swf it's checking against were both created by MXMLC to begin with):
-rw-rw-r-- 1 nathan nathan 3181508 2009-07-15 17:50 Editor.swf -rw-rw-r-- 1 nathan nathan 5756512 2009-07-15 17:50 Editor.swf.cache $ flex_sdk/bin/mxmlc -version Version 3.3.0 build 4852 $ uname -a Linux sargasso 2.6.24-19-generic #1 SMP Fri Jul 11 23:41:49 UTC 2008 i686 GNU/Linux Ubuntu 8.04